HK1087073B

HK1087073B - Ink cartridge

Info

Publication number: HK1087073B
Application number: HK06107375.4A
Authority: HK
Inventors: 佐佐木丰纪; 高木淳宏; 服部信吾; 神户智弘
Original assignee: 兄弟工业株式会社
Priority date: 2004-02-09
Filing date: 2005-02-09
Publication date: 2009-02-13

Description

Ink box

Technical Field

The present invention relates to an ink cartridge mountable to an inkjet recording apparatus.

Background

An ink jet recording apparatus having a structure allowing an ink container (hereinafter referred to as an ink cartridge) to be attached and detached is proposed in japanese laid-open patent application No. h 9-85963. The ink jet recording apparatus includes two chambers that hold ink cartridges. A porous material is filled in each chamber and a protruding portion protruding upward from the upper ends of both chambers is formed. One chamber includes a porous material connected to the air introduction opening therein, and the lower surface of the porous material of the other chamber is connected to the ink supply opening.

The ink cartridge is provided at the bottom with a through hole allowing each protruding portion to be inserted. By mounting the ink cartridge to the mounting portion, the two chambers and the interior of the ink cartridge can communicate.

Disclosure of Invention

There is a negative pressure inside the ink cartridge when the ink cartridge is in the packaging bag. When the ink cartridge is initially mounted, if the valve of the ink supply opening is opened earlier than the valve of the air introduction opening, the ink stored on the side of the recording apparatus flows back into the ink cartridge. The ink in the ink cartridge is kept in a degassed state, but if the ink that has been discharged flows back again, this state cannot be kept. In addition, when the ink flows to the ink cartridge, a meniscus of the ink formed in the nozzles of the recording head is broken. Thus, a problem of failing to discharge ink may occur.

The present invention is mainly intended to solve the above-described problems and provide an ink cartridge capable of preventing ink from flowing back into the ink cartridge when the ink cartridge is mounted, among other things. And good discharge of ink at the recording head can be maintained.

According to an aspect of the present invention, there is provided an ink cartridge configured to be mounted in an inkjet recording apparatus, the ink cartridge including: an ink chamber; an air introducing opening which introduces air into the inside of the ink chamber; a first seal member capable of blocking and allowing communication between the air introduction opening and an area outside the ink cartridge, the first seal member including a first valve seat and a first valve movable relative to the first valve seat; an ink supply opening which supplies ink from the ink chamber; a second seal member capable of blocking and allowing communication between the ink supply opening and an area outside the ink cartridge, the second seal member including a second valve seat and a second valve movable relative to the second valve seat; and a check valve provided between the second seal and the ink chamber, wherein the check valve blocks a flow of the ink from an area outside the ink supply opening to the ink chamber in the ink supply opening, wherein the first seal is configured such that the first valve is urged against the first valve seat to block a communication between the air introduction opening and the area outside the ink cartridge before the ink cartridge is mounted in the ink jet recording apparatus, and the first valve is separated from the first valve seat to allow a communication between the air introduction opening and the area outside the ink cartridge when the ink cartridge is mounted in the ink jet recording apparatus; configuring the second sealing member such that the second valve is urged against the second valve seat to block communication between the ink supply opening and an area outside the ink cartridge before the ink cartridge is mounted in the ink jet recording apparatus, and the second valve is separated from the second valve seat to allow communication between the ink supply opening and the area outside the ink cartridge when the ink cartridge is mounted in the ink jet recording apparatus; and depressurizing the ink chamber before the ink cartridge is mounted in the ink jet recording apparatus.

According to an aspect of the present invention, the air introduction opening and the ink supply opening may be formed at one side of the ink chamber.

According to an aspect of the present invention, the check valve blocks the ink supply opening only when ink flows from an area outside the ink supply opening to the ink chamber.

According to an aspect of the present invention, the air introduction opening may directly communicate with an inside of the first cylindrical wall on the first side of the ink chamber. The ink supply opening may be in direct communication with an interior of the second cylindrical wall on the first side of the ink chamber. A first seal may be provided inside the first cylindrical wall to seal the air introduction opening. A second seal may be provided inside the second cylindrical wall to seal the ink supply opening.

According to one aspect of the invention, the check valve may include a shaft portion and a membrane portion. The film portion may be positioned to face the ink supply opening at a position apart from the ink supply opening by a predetermined distance. When ink flows from the area outside the ink supply opening to the ink chamber, the thin film portion closely contacts and blocks the ink supply opening.

According to one aspect of the present invention, the check valve may include a shaft portion, a thin film portion at one end of the shaft portion, and a protrusion portion. The projection may rest on top of the ink supply opening. The thin film portion may move toward the ink supply opening when the ink flows toward the ink chamber.

According to an aspect of the present invention, the check valve may closely contact and block the ink supply opening when a predetermined amount of ink flows from an area outside the ink supply opening to the ink chamber.

According to an aspect of the present invention, when the seal on the air introducing side and the seal on the ink supplying side are opened while the ink cartridge is mounted to the recording apparatus, the ink can be prevented from flowing back from the ink supplying opening to the ink chamber, and the ink chamber can be in a depressurized state. In addition, it is possible to avoid a break in the ink degassing state due to mixing of the ink on the recording apparatus side into the degassed ink in the ink cartridge. In addition, it is possible to prevent damage to the ink meniscus inside the nozzles of the recording head, and thereby reduce defective ink discharge from the recording head. This has the effect of being able to maintain excellent recording quality at all times.

According to an aspect of the present invention, since the two sealing members can allow communication by mounting the ink cartridge from one direction, mounting of the ink cartridge to the recording apparatus becomes simple. In addition, there is an effect that the above-described occurrence of the ink backflow can be prevented even if any one of the sealing members is opened first due to the inclination of the ink cartridge during the mounting process.

According to an aspect of the present invention, a small amount of reflow can be tolerated, and thus a drastic change in pressure on the recording head side can be prevented. That is, with a structure capable of closing the valve in a normal state and opening the valve only at the time of ink supply, when the pressure on the recording side changes and increases due to the movement of the ink cartridge, the ink does not have a position where it can leak out, and the pressure on the recording side increases, thus preventing normal ink discharge. Therefore, when ink flows from the area outside the ink supply opening to the ink chamber, by simply blocking the ink supply opening with the check valve and opening the ink supply opening in a normal state, a small amount of backflow to the ink chamber can be tolerated and such a phenomenon is prevented.

According to a representative aspect of the present invention, the air to be introduced and the ink to be supplied are completely separated, thus having an effect that the air is not mixed into the ink to be supplied.

According to a representative aspect of the present invention, there are an effect that the check valve can be formed simply and inexpensively, and an effect that the pressure on the recording head side is prevented from having the above-described fluctuation, and an effect that the back flow can be prevented accurately when the back flow occurs.

According to a representative aspect of the present invention, it is possible to form the seal member with a simple structure and to simplify the mounting of the ink cartridge to the recording apparatus main body.

Drawings

Various representative embodiments of the present invention will be described in detail with reference to the accompanying drawings, in which:

fig. 1 is a schematic view of a representative ink cartridge according to the present invention and a representative inkjet recording apparatus according to the present invention, in which the ink cartridge is mounted to the inkjet recording apparatus;

fig. 2A and 2B are sectional views showing the structure of one representative ink cartridge according to the present invention: fig. 2A shows the ink cartridge before the ink cartridge is mounted to the inkjet recording apparatus, and fig. 2B shows the ink cartridge after the ink cartridge is mounted to the inkjet recording apparatus;

figures 3A-3E show a representative valve element according to the present invention: FIG. 3A is a plan view, FIG. 3B is a side view, FIG. 3C is a sectional view taken along the line I-I in FIG. 3A, FIG. 3D is a sectional view taken along the line II-II in FIG. 3A, and FIG. 3E is a bottom view;

figures 4A-4C illustrate one representative valve element according to the present invention: fig. 4A is a plan view, fig. 4B is a side view, and fig. 4C is a bottom view;

fig. 5A and 5B show a representative mounting portion according to the present invention: FIG. 5A is a sectional view taken along the line III-III in FIG. 5B, and FIG. 5B is a bottom view;

fig. 6A and 6B show a representative mounting portion of fig. 5B: FIG. 6A is a sectional view taken along the line IV-IV in FIG. 5B, and FIG. 6B is a sectional view taken along the line V-V in FIG. 5B;

FIG. 7 is a perspective view of a representative check valve according to the present invention;

FIGS. 8A-8C illustrate one representative ink cartridge according to the present invention: fig. 8A is a front view, fig. 8B is a side view, and fig. 8C is a bottom view;

FIG. 9 is a perspective view of the ink cartridge of FIGS. 8A-8C;

fig. 10 is a sectional view showing the structure of one representative ink cartridge according to the present invention before the ink cartridge is mounted to the inkjet recording apparatus;

FIGS. 11 and 11B are cross-sectional views showing one representative ink extraction tube and one representative valve member in accordance with the present invention: fig. 11A shows the ink extraction tube before it enters the guide passage and contacts the valve element, and fig. 2B shows the ink extraction tube contacting the valve element and pushing the valve element toward the ink chamber;

FIG. 12 is an oblique perspective view of a representative valve member according to the present invention;

FIG. 13 is a perspective view of the inside of the lower portion of a representative ink cartridge body according to the present invention;

FIG. 14 is a cross-sectional view of section VI of FIG. 13;

FIG. 15 is a cross-sectional view of section VII of FIG. 13;

FIG. 16 is a cross-sectional view of section VIII of FIG. 13;

FIG. 17 is a cross-sectional view of section IX of FIG. 13;

FIG. 18 is a perspective view of the inside of the lower portion of a representative ink cartridge body according to the present invention;

FIG. 19 is a perspective view of the inside of the lower portion of a representative ink cartridge body according to the present invention;

fig. 20A and 20B are cross-sectional views of fig. 19: FIG. 20A is a sectional view taken along section X, and FIG. 20B is a sectional view taken along section XI;

fig. 21 is a sectional view showing the structure of one representative ink cartridge according to the present invention before the ink cartridge is mounted to the ink jet recording apparatus;

FIG. 22 is a bottom view of a representative main housing according to the present invention;

fig. 23A and 23B are sectional views of a representative ink cartridge according to the present invention, in which the valve element is removed from the valve seat portion: fig. 23A shows the ink cartridge mounted correctly into the mounting portion, and fig. 23B shows the ink cartridge mounted incorrectly into the mounting portion;

fig. 24 is a sectional view showing the structure of one representative ink cartridge according to the present invention before the ink cartridge is mounted to the ink jet recording apparatus;

FIGS. 25A and 25B show an enlarged front end portion of one representative air intake in accordance with the present invention: fig. 25A is a sectional view, and fig. 25B is a top view; and

FIGS. 26A and 26B illustrate an enlarged front end portion of one representative air intake in accordance with the present invention: fig. 26A is a sectional view, and fig. 26B is a top view.

Detailed Description

An embodiment of the present invention is described below with reference to the drawings. Referring first to the schematic view of fig. 1, which shows a typical ink cartridge 1 and a typical inkjet recording apparatus 2 according to the present invention, the ink cartridge 1 is mounted on the inkjet recording apparatus 2.

The ink cartridge 1 is formed to be detachably mountable to the ink jet recording apparatus 2, and the ink jet recording apparatus 2 is provided with a recording head 7 for ejecting ink. The ink cartridge 1 stores ink to be supplied to the recording head 7.

The ink cartridge 1 is provided with a hollow, box-like main body casing 1a, and a top 1b sealing the top surface of the main body casing 1 a. The ink to be supplied to the recording head 7 is stored in an ink chamber 16 formed in the main body casing 1a (see fig. 2A and 2B). In addition, a plurality of ink cartridges filled with inks of respective colors such as cyan, magenta, yellow, and black, respectively, can be mounted in the inkjet recording apparatus 2. Color printing is thus possible.

The inkjet recording apparatus 2 is provided with a mounting portion 3, an ink tank 5, a recording head 7, a carriage 8, a carriage shaft 9, a transport mechanism 10, and a cleaning device 11, wherein the ink cartridge 1 can be mounted on the mounting portion 3, the ink tank 5 stores ink supplied from the ink cartridge 1 through an ink supply tube 4, the recording head 7 ejects the ink stored in the ink tank 5 onto a recording sheet 6, the ink tank 5 and the recording head 7 are mounted on the carriage 8, the carriage 8 can move in two linear directions, the carriage shaft 9 serves as a guide, the carriage 8 moves in the two linear directions by the carriage shaft 9, and the transport mechanism 10 transports the recording sheet 6.

The mounting portion 3 is composed of a base portion 3a and guide portions 3b, wherein the guide portions 3b are provided on both sides of the base portion 3 a. An extended hollow ink extraction tube 12 sucks ink stored in the ink cartridge 1, and an air supply opening 91 that introduces outside air into the interior of the ink cartridge 1 is disposed on the base portion 3 a.

One end of the ink extraction tube 12 communicates with the ink flow passage 94, and is connected to the ink tank 5 through the ink supply tube 4. The air supply flow passage 92 and the air intake opening 93 communicate with the air supply opening 91 (see fig. 5A and 5B).

The ink cartridge 1 is mounted in a direction (arrow X direction) perpendicular to the mounting portion 3. When mounted, the ink extraction tube 12 opens a valve system 23 described later provided inside the ink cartridge 1 and communicates with the inside of the ink chamber 16. In addition, the air supply opening 91 communicates with the interior of the ink chamber 16.

A plurality of nozzle openings are provided in a surface of the recording head 7 facing the recording paper 6. By driving an actuator constituted by a piezoelectric element, the ink stored in the ink tank 5 is ejected from the nozzle hole toward the recording paper 6. During an actual recording operation, the carriage 8 on which the recording head 7 is mounted reciprocates to perform recording on the recording paper 6.

In addition, the recording head 7 is located at a higher height position than the mounting portion 3. Since there is a head difference between the ink cartridge 1 mounted on the mounting portion 3 and the nozzle holes, negative pressure (back pressure) is applied to the ink in the nozzle holes.

The cleaning device 11 is disposed outside the recording area so as to be opposed to the recording head 7. The cleaning device 11 is provided with: a cleaning cap 11a covering the surface of the recording head 7 where the nozzle holes are formed; a waste ink tube 11b communicating with the cleaning cap 11 a; and a pump 11c that pumps ink from the nozzle holes into the waste ink tube 11 b.

When the cleaning operation is performed, the carriage 8 is moved to the cleaning operation performing position, and the surface of the recording head 7 where the nozzle holes are formed is covered with the cleaning cap 11 a. The pump 11c is driven in this state to suck poor quality ink containing bubbles and the like accumulated in the recording head 7. These drawn-out poor-quality inks are stored in a waste ink tank, not shown, via the waste ink tube 11 b. The recording operation and the purging operation are controlled by a Central Processing Unit (CPU) (not shown) mounted on the inkjet recording apparatus 2.

The structure of the ink cartridge mounted in the inkjet recording apparatus 2, particularly the structure of a portion in fig. 1, is explained below with reference to fig. 2A and 2B. Fig. 2A and 2B are sectional views showing the structure of the ink cartridge 1 according to the present invention. Fig. 2A shows the ink cartridge 1 before the ink cartridge 1 is mounted to the inkjet recording apparatus 2. Fig. 2B shows the ink cartridge 1 after the ink cartridge 1 is mounted to the inkjet recording apparatus 2.

The ink cartridge 1 includes a main body casing 1a having an ink chamber 16, a top 1b covering an open upper surface of the main body casing 1a, and a cap member 1f covering a bottom wall 1e of the main body casing 1 a. On the cap 1f, two exposure holes 1fa, 1fb are formed on the mounting portion 3 side to expose valve systems 23, 24 described later. When the ink cartridge 1 is formed, the top 1b and the cap 1f are fused together with the main body casing 1 a. The material of which the main body casing 1a, the top 1b, and the cap 1f are made may be a resin material.

An ink supply opening 21 is formed in the bottom wall 1e, and opens outward for supplying ink in the ink chamber 16 outward. The ink supply opening 21 directly communicates with a communication chamber 30 provided inside a cylindrical wall 21a, the cylindrical wall 21a being formed integrally with the bottom wall 1e and projecting from the lower first surface of the bottom wall 1 e. In addition, an air introduction opening 26 is formed in the bottom wall 1e, and is opened outward for introducing air into the ink chamber 16. The air introduction opening 26 directly communicates with a communication chamber 50 provided inside a cylindrical wall 26a, which cylindrical wall 26a is formed integrally with the bottom wall 1e and projects from the lower surface of the bottom wall 1 e. When the ink cartridge 1 is mounted to the mounting portion 3, the ink extraction tube 12 is inserted into the communication chamber 30.

The check valve 60 is positioned in the ink supply opening 21 and faces the ink supply opening 21. The check valve 60 is constructed by integrally forming an umbrella-shaped elastic film portion 60b and a shaft portion 60c from a synthetic material, the film portion 60b facing the lower surface of the ink supply opening 21, and one end of the shaft portion 60c holding the film portion 60 b. The shaft portion 60c is inserted into the shaft hole 1n in the bottom wall 1e so as to be slidable in the up/down direction. Normally, the convex portion 60a is in contact with the top surface of the bottom wall 1e, and the thin film portion 60b is spaced from the ink supply opening 21 at the contact position to allow ink to flow from the ink chamber 16 to the valve member 32. When the ink flows from the ink extraction tube 12 to the ink chamber 16, such flow is prevented by raising the film portion 60b and sealing the ink supply opening 21.

A cylindrical member 25 surrounding the air introduction opening 26 is provided on the bottom wall 1e and projects into the ink chamber 16. This protrusion of the cylindrical member 25 allows air supplied from the outside to flow to the upper portion of the ink chamber 16 through the flow passage inside the cylindrical member 25. The opening in the upper portion of the air introduction opening 26 is positioned higher than the ink surface.

The valve systems 23, 24 are fixed to the ink supply side communication chamber 30 and the air introduction side communication chamber 50, respectively, which are examples of seals.

The valve system 23 is provided with a support member 46 integrally made of a rubber elastic member, and a valve member 32 made of a resin material. The support member 46 has a substantially cylindrical outer shape, and is constituted by a valve seat portion 46a and an urging portion 46b that are integrally formed, the urging portion 46b being closer to the ink chamber 16 than the valve seat portion 46a, the support member 46 further having an outer wall 33 on the side of the valve seat portion 46a opposite to the urging portion 46 b. The urging portion 46b urges the valve element 32 in a direction toward the valve seat portion 46a, and the valve element 32 is accommodated in a space between the valve seat portion 46a and the urging portion 46 b.

The outer wall 33 has a connecting portion 33a projecting radially outward. The communication chamber 30 has a stepped surface 44, and the communication chamber 30 has an increased diameter in the outward direction so as to accommodate the connection portion 33 a. The projection 43 is formed on one surface of the connecting portion 33a facing the step surface 44. The cap 1f is fixed to the main body casing 1a by pressing the projection 43 onto the stepped surface 44 and placing the connecting portion 33a between the stepped surface 44 and the cap 1f while the projection 43 is deformed. This can prevent ink from flowing out from the space formed between the outer wall 33 of the valve system 23 and the inner wall of the communication chamber 30.

The opening 41 is formed in the valve seat portion 46a through the center of the valve seat portion 46a in the axial direction. In addition, an introduction passage 40 into which the ink supply extraction tube 12 is inserted is formed on the outer wall 33 in such a manner that the introduction passage 40 communicates with the opening 41.

The inner diameter of the introduction passage 40 is smaller than the outer diameter of the ink extraction tube 12 so that the outer wall 33 is in contact with the ink extraction tube 12. The opening 41 is formed larger than the inner diameter of the introduction passage 40 and the outer diameter of the ink extraction tube 12. The introduction passage 40 is formed in a tapered shape at an end on the side where the ink extraction tube 12 is inserted, and it gradually widens in the outward direction.

The side wall portion 36 forms a pushing portion 46b which extends toward the ink chamber 16 in the form of a cylinder around the periphery of the opening 37a and stands up from the valve seat portion 46a, and the extending portion 37 connected to the side wall portion 36 projects inward so as to contact the side of the valve member 32 opposite to the ink chamber 16. The extension 37 has an opening 37a at the center of the extension 37.

The pushing portion 46b pushes the valve member 32 in a direction to bring the valve member 32 into contact with the valve seat portion 46a, with the elastic force of the side wall portion 36 and the extension portion 37, and normally brings the valve member 32 into contact with the valve seat portion 46 a. In addition, by inserting the ink extraction tube 12 into the introduction passage 40 to push the valve member 32 toward the ink chamber 16, the side wall portion 36 is expanded and the extension portion 37 is inclined, so that a gap is present through which ink can pass between the valve member 32 and the valve seat portion 46 a.

Figures 3A-3B show the valve member 32 in detail. The valve member 32 has a bottom portion 57 and a valve side wall portion 56 projecting perpendicularly from the outer periphery of the bottom portion 57. A communication passage 58 is continuously formed through the bottom portion 57 and the valve side wall portion 56.

The bottom portion 57 has a protruding piece 39, the protruding piece 39 protrudes toward the valve seat portion 46a and is formed in a ring shape on one end surface facing the valve seat portion 46a, and the protruding piece 39 is located inside the communication passage 58 and outside the opening 41 in terms of its position in the radial direction. When the valve element 32 is in the state of being accommodated in the support 46, the valve side wall portion 56 is in close contact with and pressed against the extension portion 37 of the pushing portion 46 b. By pressing the protrusion 39 downward, the protrusion 39 elastically deforms the valve seat portion 46a and closely contacts the upper surface of the valve seat portion 46 a.

The valve system 24 on the air introduction side is similar to the valve system 23 and has a support member 46 integrally formed of a rubber elastic member and a valve member 65 made of a ribbed material.

The support 46 has a valve seat portion 46a, a pushing portion 46b, and a sealing portion 63. The valve seat portion 46a and the urging portion 46b have similar functions to the corresponding portions of the valve system 23.

An opening 41 is formed at substantially the center of the valve seat portion 46 a. A cylindrical seal portion 63 surrounds the opening 41 and is integrally formed at a lower portion of the valve seat portion 46 a.

As shown in fig. 4A to 4C, the valve member 65 has a cylindrical portion 66 at its top, an operating member 67 at its bottom, and a valve portion 68 at its substantially middle portion. Similar to the valve member 32 shown in fig. 3A to 3E, the valve portion 68 has a bottom portion 57, a valve side wall portion 56 projecting perpendicularly from the outer periphery of the bottom portion 57, and a communication passage 58 formed continuously through the bottom portion 57 and the valve side wall portion 56. These parts function as corresponding parts of the valve member 32. And thus their description is omitted.

The cylindrical portion 66 has a cylindrical shape rising from the bottom portion 57. When the ink cartridge 1 is properly mounted in the mounting portion 3, the cylindrical portion 66 is positioned so that even if the valve member 65 is pushed up from the valve seat portion 46a, a gap still exists between the top end of the cylindrical portion 66 and the inner surface of the cylindrical member 25, and communication between the ink chamber 16 and the opening 41 of the valve seat portion 46a can be ensured.

The operating member 67 is a projecting portion that extends vertically downward from the bottom portion 57, and is formed with a circular outer shape 67a and a recess 67b that extend in the radial and axial directions. The operating piece 67 extends downward through the opening 41 of the support 46 and has a lower end slightly higher than the lower end of the seal portion 63. The recess 67b may be utilized such that the cross-sectional area of the air passage between the opening 41 and the recess 67b is large.

Fig. 5A-6B show details of the mounting portion 3. On the air supply side, the recess 3d is located on the base portion 3a of the mounting portion 3 at a position facing the valve system 24. The recess 3d has a side that engages with the seal portion 63 when the ink cartridge 1 is mounted. At the bottom of the recess 3d, an air supply opening 91 is formed through the wall constituting the base portion 3a at a position not facing the lower end of the operation member 67 inside the seal portion 63. The air supply opening 91 may be formed as one slit having a width smaller than the diameter of the operation member 67 but a length longer than the diameter of the operation member 67 or as a plurality of slits in a radial shape.

A groove-shaped air supply flow passage 92 is formed on the lower surface of the wall constituting the base portion 3 a. The air supply flow passage 92 is connected at one end thereof increased in cross-sectional area to the air supply opening 91, and at the other end thereof to an air intake opening 93 formed through a wall constituting the base portion 3a in the up/down direction. A part of the air supply flow path 92 is formed along the lower surface of the wall in the form of a plurality of curves for suppressing the flow of air and preventing volatilization of ink components and moisture when the air introduction opening 26 of the ink cartridge 1 is connected.

The air intake opening 93 is open on the upper surface of the base portion 3a but spaced apart from the bottom surface of the mounted ink cartridge 1 by a certain distance, so that the ink cartridge 1 is supplied with air via the air supply flow passage 92 and the air supply opening 91. The upper surface of the air intake opening 93 may be covered with a porous elastic body 3c described later so as to be able to ventilate with the outside air.

On the ink extraction side, an ink extraction tube 12 is integrally formed on and projects from the upper surface of the wall constituting the base portion 3a, and an ink flow passage 94 is formed on the lower surface. An end 94a of the ink flow passage 94 is connected to a lower end of the ink flow passage 94 formed in the up/down direction through the ink extraction tube 12, an end 94b opens a part of an upper surface of the base portion 3a extending to the outside of the guide portion 3b, and the ink supply tube 4 is connected to the upper surface.

A communication opening 81a that opens the ink flow passage 94 to the outside is formed at the tip of the ink extraction tube 12. With the communication opening 81a, communication is ensured between the ink flow passage 94 and the ink chamber 16 even if the tip end contacts the valve member 32. A porous elastic body 3c such as sponge is positioned on the top surface of the base portion 3a around the ink extraction tube 12. The porous elastic body 3c sucks up ink that may leak out of the valve system 23.

The mounting portions 3 of the plurality of ink cartridges are provided at a plurality of positions. Each wall constituting the base portion 3a and the guide portion 3b integrally extends in the direction in which the ink cartridge is disposed. The ink extraction tube 12, the ink flow passage 94, the guide portion 3b, the air supply opening 91, and the air supply flow passage 92 described above are provided for each mounting position. As shown in fig. 5B, the end portions 94a, 94B of each ink flow channel 94, which are respectively connected to each corresponding ink supply tube 4, are arranged laterally at the extension of the base portion 3 a.

In addition, the ink flow path 94 and the air supply flow path 92 described above are formed by covering the open lower surfaces of the grooves with a cover member such as a resin film 95. The film 95 is fixed by fusion to the lower end surfaces of the ribs 94c, 92c, which ribs 94c, 92c form the peripheries of the ink flow path 94 and the air supply flow path 92, respectively. The ink flow path 94 and the air supply flow path 92 at the same mounting position are covered with a single film 95.

The mounting of the ink cartridge 1 achieved at the mounting portion 3 of the inkjet recording apparatus 2 is described below with reference to fig. 2A and 2B. Fig. 2A shows a state in which the ink cartridge 1 has not been mounted in the mounting portion 3 of the inkjet recording apparatus 2. In this state, the elastic force of the urging portion 46b of the support member 46 presses the valve element 32 on the ink supply side and the valve element 65 on the air introduction side against the valve seat portion 46a, and therefore neither of the valve systems 23, 24 is opened.

As shown in fig. 2B, when the ink cartridge 1 is mounted, the front end of the ink extraction tube 12 pushes the valve element 32 and the side wall portion 36 of the support member 46 so that the valve element 32 is projected and separated from the valve seat portion 46a, thus opening the valve system 23 on the valve supply side. The ink flow passage extends to the ink extraction tube 12 via the ink chamber 16, the ink supply opening 21, the opening 37a of the valve system 23, the communication passage 58, and the gap between the valve member 32 and the valve seat portion 46 a. Whereby the ink is supplied to the recording head 7.

On the other hand, on the air supply side, the front end of the operation member 67 contacts the bottom of the recess 3d, thus lifting up the valve member 65. As the side wall portion 36 of the support 46 expands, the valve portion 68 of the valve member 65 separates from the valve seat portion 46 a. The valve system 24 is thus open.

Meanwhile, in a state where the communication is blocked from the outside, the sealing portion 63 closely contacts the recess 3d, which allows communication between the air introduction opening 26 of the ink cartridge 1 and the air supply opening 91 of the mounting portion 3. This forms an air flow passage to the upper portion of the ink chamber 16 via the air intake opening 93, the air supply flow passage 92 and the air supply opening 91 of the mounting portion 3, the opening 41, the gap between the valve member 65 and the valve seat portion 46a of the valve system 24, the communication passage 58, the air introduction opening 26, and the flow passage inside the cylindrical member 25.

In this embodiment, since the ink extraction tube 12 is joined together with the introduction passage 40, the position of the valve system 23 can be adjusted. However, the operation member 67 may contact virtually any portion of the bottom of the recess 3d except for the air supply opening 91 which cannot be blocked. Therefore, strict dimensional tolerances are not required for the respective positional relationships when manufacturing the ink cartridge 1, which are the positional relationship between the ink supply opening 21 and the air introduction opening 26, the positional relationship between the valve systems 23 and 24, and the positional relationship between the ink extraction tube 12 of the mounting portion 3 and the air supply opening 91. In addition, when the user performs the mounting operation of mounting the ink cartridge 1 to the mounting portion, the mounting operation becomes simple.

It will be appreciated that various modifications are possible. For example, in the above-described embodiment, the valve system 24 on the air supply side is provided with the operation member 67 protruding to the outside of the ink cartridge, and the ink extraction tube 12 of the mounting portion 3 protrudes on the ink extraction side. However, the valve system 23 on the ink extracting side may be provided with an operating member that protrudes outside the ink cartridge 1.

In addition, in this embodiment, the ink supply opening 21 and the air introduction opening 26 are sealed using a valve system. However, the opening on the side where the valve system is not used may be sealed with rubber, and a needle-shaped ink extraction tube may protrude from the mounting portion.

As shown in fig. 2A, the operating piece 67 is positioned such that its lower end is slightly higher than the lower end of the seal portion 63. The valve member 65 closely contacts the valve seat portion 46 a. Similarly, on the ink supply side, the valve element 32 closely contacts the valve seat portion 46a with the pushing portion 46 b. As shown in fig. 2B, on the ink supply side, when the ink cartridge 1 has been mounted, the front end of the ink extraction tube 12 pushes up the valve member 32 to open the valve system 23.

On the air introducing side, the front end of the operation member 67 contacts the bottom of the recess 3d, and relatively moves the valve seat portion 46a of the support 46 downward to open the valve system 24.

The ink cartridge 1 is packaged under reduced pressure. The ink chamber 16 is also subjected to a pressure reduction process. When the valve system 24 on the air introduction side and the valve system 23 on the ink supply side are opened almost simultaneously, ink flow from the ink extraction tube 12 to the ink chamber 16 occurs. The check valve 60 prevents the ink remaining in the flow passage between the ink extraction tube 12 and the recording head 7 from flowing back. In addition, air can flow quickly from the air supply opening 91 to the upper portion of the ink chamber 16 through the cylindrical member 25. Thus, even if ink enters the cylindrical member 25 during transportation due to the falling of the packaged ink cartridge 1, the ink returns to the ink chamber 16 with the flow of air. If the ink cartridge 1 is tilted with respect to the mounting portion 3 during mounting of the ink cartridge 1 and the valve element 32 on the ink supply side is opened earlier than the valve element 65 on the air introduction side, the above-described rapid flow of ink from the ink extraction tube 12 to the ink chamber 16 occurs. But this flow is prevented because the check valve 60 is lifted by the flow so that the thin film portion 60d closes the ink supply opening 21. It is preferable to appropriately set the lengths of the operation member 67 of the ink extraction tube 12 and the valve member 65 so that the valve system 24 on the air introduction side opens earlier than the valve system 23 on the ink supply side, thereby preventing quick back flow of ink from the ink extraction tube 12.

In a normal state, the film portion 60d of the check valve 60 descends to a position away from the ink supply opening 21 due to its own weight. Ink is supplied from the ink chamber 16 to the recording head 7 via the ink supply opening 21, the communication passage 58 of the valve element 32, and the ink extraction tube 12. As the ink from the ink chamber 16 flows, air is supplied from the air supply opening 91 to the upper portion of the ink chamber 16 via the cylindrical member 25. At this time, the cylindrical portion 66 of the valve member 25 on the air introduction side is spaced apart from the inner portion of the cylindrical member 25 by a certain distance to secure the air flow passage.

In addition, during the recording operation, the ink in the ink supply tube 4 moves with the movement of the carriage 8 by inertia, and the pressure of the ink supply tube 4 varies. However, since the check valve 60 causes the ink supply opening 21 to be in the open state in the normal state as described above, a weak flow of ink between the ink extraction tube 12 and the ink chamber 16 due to a pressure change can be allowed. Thus, pressure variation in the recording head 7 can be reduced, thereby stably discharging ink.

It should be understood that various modifications may be made to the above-described embodiment, for example, the check valve 60 is formed in an umbrella shape by an umbrella-shaped portion and a shaft portion. However, the check valve 60 may have other configurations, such as one side of a rectangular membrane secured to allow the other side to open and close.

In addition, the air introduction passage of the mounting portion may be similar to the ink extraction tube 12, i.e., have a hollow cylindrical shape that protrudes, while the valve system 24 on the air communication side may have the same structure as the valve system 23 on the ink supply side. In addition, the ink extraction tube 12 may not have a shape protruding from the mounting portion, while the valve system 23 on the ink supply side may have the same structure as the valve system 24 on the air communication side.

Further, the valve systems 23, 24 may be replaced with rubber stoppers which are engaged with the communicating chambers 30, 50 and through which the hollow needle-shaped ink supply tubes and the air introduction tubes protruding from the mounting portions are inserted.

The check valve 60 is further explained below with reference to fig. 7. Fig. 7 is a perspective view of the check valve 60. The check valve 60 is integrally formed of a resin material having elasticity, and has an umbrella-shaped film portion 60b facing the ink supply opening 21 and a shaft portion 60c connected to the film portion 60 b. A projection 60a is formed on the shaft portion 60 c. This shaft portion 60c can be slidably inserted into a shaft hole 1n formed near the ink supply opening 21. In a normal state, the convex portion 60a falls vertically to engage with the top surface of the bottom wall 1e due to the weight of the check valve 60 itself, and the thin film portion 60b leaves a gap to the ink supply opening 21. Therefore, in the normal state, the ink in the ink chamber 16 can flow from the ink supply opening 21 to the communication chamber 30. On the other hand, when a flow from the communication chamber 30 to the ink chamber 16 occurs, the film portion 60b rises together with the shaft portion 60c, and the film portion 60b tightly closes the ink supply opening 21 and inhibits such a backflow.

An ink cartridge 1 according to another embodiment of the present invention is described in detail below.

As shown in fig. 8A to 10, the ink cartridge 1 is provided with a main body casing 1a, a valve system 23, a valve system 24, a light shielding mechanism 22 that shields light emitted from a light emitting portion of a sensor 14 that detects the amount of remaining ink, and a cap member 1f that covers a lower end portion of the main body casing 1 a.

The main body casing 1a is formed of a synthetic resin having light transmittance. As shown in fig. 10, the bottom wall 1e extends horizontally in the main body casing 1a and the bottom wall 1e divides the internal space of the main body casing 1a into the ink chamber 16 on the upper side and the two communicating chambers 30, 50 on the lower side. The corresponding ink fills the ink chamber 16, and the valve system 23 and the valve system 24 are accommodated in the two communication chambers 30, 50, respectively. On the bottom surface of the ink chamber 16, four ink supply openings 70a-70d (see fig. 13) are provided, which supply the ink in the ink chamber 16 to the inkjet recording apparatus 2 via the valve system 23. The internal structure of the ink chamber 16 that guides ink to the four ink supply openings 70a-70d will be described below.

As shown in fig. 10, a protruding portion 34 protruding slightly outward is formed at a substantially central position in the height direction of the side wall portion of the main body casing 1 a. A light blocking plate 59 of the light blocking mechanism 22 described later is located in the space inside the protruding portion 34. In addition, when in a state where the ink cartridge 1 is mounted in the mounting portion 3, the protruding portion 34 is sandwiched between the light emitting portion and the light receiving portion of the sensor 14 provided at the mounting portion 3. In addition, the top 1b is fused to the top end portion of the main body casing 1 a. Thus, the top 1b seals the ink chamber 16 in the main body casing 1 a.

An ink filling hole 17 for filling ink into the ink chamber 16 of the empty ink cartridge 1 is formed between the two communicating chambers 30, 50. A stopper 18 formed of synthetic rubber is press-fitted into this ink injection hole 17. In addition, the depth end of the ink injection hole 17 connects the ink chamber 16 in the main body casing 1 a. An ink filling needle (not shown) is inserted into the ink filling hole 17 via a stopper 18 to fill the ink chamber 16 with ink through the ink filling needle.

A cylindrical portion 38 communicating with the ink chamber 16 and the communication chamber 30 is integrally formed on a part of the bottom wall 1 e. At the lower end of the cylindrical portion 38, a thin film portion 42 is provided, the thin film portion 42 closing the communication passage formed in the cylindrical portion 38. On the other hand, two cylindrical portions 47 and 48 communicating with the ink chamber 16 and the communication chamber 50 are integrally formed on a part of the bottom wall 1 e. At the lower end of the cylindrical portion 48, a film portion 49 is provided, and the film portion 49 closes the communication passage formed in the cylindrical portions 47, 48. In addition, on the upper side of the cylindrical portion 47, a cylindrical member 25 extending to the upper end portion of the ink chamber 16 is provided.

As shown in fig. 10 to 11B, the valve system 23 is provided with a substantially cylindrical support member 46 formed of an elastomer having elasticity and the valve element 32 accommodated in the support member 46. The support 46 is constituted by a pressing portion 46b, a valve seat portion 46a, and a connecting portion 33a which are integrally formed, and the positions of these portions from the upper side (ink chamber 16 side) of the support 46 are the pressing portion 46b, the valve seat portion 46a, and the connecting portion 33a in this order.

The lower surface of the valve element 32 is brought into contact with the upper surface of the valve seat portion 46a (the end surface on the ink chamber 16 side), and an opening 41 extending in the up/down direction is formed in a portion at the center axis of the valve seat portion 46 a. An introduction passage 40 communicating with the opening 41 and extending downward is formed in the connection portion 33a, and the introduction passage 40 is formed in a taper shape having a larger diameter toward the lower side. An annular groove 40a is formed around the introduction passage 40. The wall portion forming the introducing passage 40 is easily elastically deformed in the direction in which the diameter of the introducing passage 40 increases. Therefore, when the ink extraction tube 12 is inserted into the introduction passage 40, the sealability of the introduction passage 40 and the ink extraction tube 12 is increased, and ink leakage is prevented to a large extent. In addition, even if the ink extraction tube 12 is inserted into the introduction passage 40 in an inclined state or an eccentric state, since the wall portion can be deformed in a direction in which the diameter of the introduction passage 40 increases, the ink extraction tube 12 can be inserted into the introduction passage 40 accurately.

The pushing portion 46b has a cylindrical side wall portion 36 rising from the peripheral portion of the valve seat portion 46a toward the ink chamber 16 side, and an extension portion 37 projecting in a radially inward direction integrally from the upper end of the side wall portion 36. The lower surface of the extension portion 37 contacts the valve member 32. The valve member 32 is pushed downward by the elastic force of the side wall portion 36 and the extension portion 37. In addition, an opening 37a is formed inside the extension portion 37, so that the integrally formed side wall portion 36 and extension portion 37 are easily elastically deformed.

As shown in fig. 11A to 12, the valve element 32 has a bottom portion 57 that contacts the valve seat portion 46a, a cylindrical valve side wall portion 56 that extends from the periphery of the bottom portion 57 toward the ink chamber 16 side, and a piercing portion 52 that projects from the central portion of the bottom portion 57 toward the ink chamber 16 side, the piercing portion 52 projecting farther toward the ink chamber 16 side than the valve side wall portion 56.

A projecting member 39 projecting to the side of the valve seat portion 46a is formed on the lower surface of the bottom portion 57. When the pressing portion 46b presses the valve member 32 to the side of the valve seat portion 46a and when the protruding member 39 closely contacts the upper surface of the valve seat portion 46a, the valve member 32 closes the opening 41 of the valve seat portion 46a and closes the ink supply flow passage. In addition, a plurality of communication passages 53 connecting the upper and lower spaces of the valve member 32 are formed at equal intervals in the circumferential direction on a portion of the bottom portion 57 outside the periphery of the projecting member 39 and inside the periphery of the valve side wall portion 56.

As shown in fig. 11A to 12, the piercing portion 52 is constituted by four plate members 52a, 52b, 52c, 52d which are fitted into a cross shape in plan view and which are directed upward at a substantially central portion of the bottom portion 57. In addition, grooves 54 extending in the up/down direction are formed between the four plate members 52a-52d, respectively. In addition, the piercing portion 52 projects upward through the opening 37a inside the valve seat portion 46 b. As shown in fig. 10, the front end of the puncturing part 52 is located at a position slightly lower than the film part 49.

When the ink cartridge 1 is mounted to the mounting portion 3, the ink extraction tube 12 is inserted into the introduction passage 40. Then, the valve member 32 is lifted up against the urging force of the urging portion 46b by the front end of the ink extraction tube 12. The valve element 32 moves upward while deforming the pressing portion 46b, and the protruding piece 39 of the valve element 32 is separated from the valve seat portion 46 a. At this time, as shown in fig. 10 and 11B, since the leading end of the piercing portion 52 of the valve element 32 that has moved upward pierces the thin film portion 42, the ink in the ink chamber 16 flows into the communication chamber 30, and the ink is supplied from the ink extraction tube 12 to the ink jet recording head 2 side via the communication passage 53 of the valve element 32.

The valve system 24 is provided with a support member 46 and a valve member 32 accommodated in the support member 46, and has the same structure as the valve system 23. That is, in order to close the opening 41, the urging portion 46b, which is tightly connected to the valve seat portion 46a of the support 46, urges the valve element 32 downward. In addition, when the ink cartridge 1 is mounted to the mounting portion 3, the air introduction tube 13 is inserted into the introduction passage 40 formed at the support 46, and the valve member 32 is moved upward, similar to the valve system 23, so that the piercing portion 52 pierces the film portion 49 of the cylindrical portion 48. Then, the outside air flows from the air introduction pipe 13 into the communication chamber 50 through the communication passage 53 of the valve member 32, and the air is introduced into the upper portion of the ink chamber 16 through the internal passage of the introduction passage 40, the opening 41, and the cylindrical member 25.

As shown in fig. 10, the light shielding mechanism 22 is provided in a space below the ink chamber 16. The light blocking mechanism 22 is provided with a light blocking plate 59 through which light cannot pass, a hollow float 61, a link 62 connecting the light blocking plate 59 and the float 61, and a support stand 64 provided on the upper side of the bottom wall 1e and rotatably supporting the link 62. The light blocking plate 59 and the float 61 are provided at the ends of the connecting member 62, respectively. The link 62 is arranged to be rotatable about a rotation point of the support stand 64 in a vertical plane perpendicular to the bottom wall 1 e.

The light blocking plate 59 is a thin plate member parallel to the vertical plane and having a predetermined area. When the ink cartridge 1 is mounted on the mounting portion 3, the light emitting portion and the light receiving portion of the sensor 14 provided at the mounting portion 3 are positioned at the same height as the projecting portion 34 formed on the side wall portion of the main body casing 1 a. When the light-blocking panel 59 is located in the space inside the protruding portion 34, the light-blocking panel 59 can block light emitted from the light-emitting portion of the sensor 14, transmitted through the wall portion of the main body casing 1a and the ink in the ink chamber 16. The float 61 is a cylindrical member whose inside is filled with air. The specific gravity of the entire float is smaller than that of the ink in the ink chamber 16.

Therefore, when the amount of ink remaining in the ink chamber 16 is large and when the entire float 61 provided at one end of the link 62 is positioned in the ink, the float 61 floats up by buoyancy, and the light-blocking plate 59 provided at the other end blocks the light from the light-emitting portion (the above-described positional relationship is shown by a solid line in fig. 10). However, when the amount of remaining ink remaining in the ink chamber 16 becomes small, a part of the float 61 is exposed from the ink surface, the buoyancy applied to the float 61 decreases, and the float 61 lowers. The light-blocking plate 59 then moves to above the protruding portion 34 and to a position where the light-blocking plate 59 no longer blocks the light from the light-emitting portion (the above-described positional relationship is shown by a chain line in fig. 10). Therefore, the light from the light emitting portion passes through the protruding portion 34 along a straight optical path and the light receiving portion receives the light. A state in which the amount of ink remaining in the ink chamber 16 is small can be detected by the sensor 14.

As shown in fig. 8A to 10, a cap 1f is fixed to the main body casing 1a by ultrasonic bonding or the like so as to cover the lower end of the main body casing 1 a. At positions of the bottom of the cap 1f corresponding to the valve system 23 and the valve system 24, respectively, two sealing portions 63 are formed to protrude downward, respectively. The sealing portion 63 makes it difficult for the ink around the inlet of the ink extracting tube 12 or the air introducing tube 13 to stick to the tabletop when the ink cartridge 1 is placed on the tabletop.

The internal structure of the ink chamber 16 that guides the ink in the ink chamber 10 to the ink supply openings 70a-70d is described below.

As shown in fig. 13, a deep portion 72a is formed on the upper surface of the bottom wall 1e forming the bottom surface of the ink chamber 16 at a position slightly lower than the periphery. Further, a plate 71 is provided at a substantially central position of the deep portion 72a in plan view. Four ink supply openings 70a to 70d that supply the ink in the ink chamber 16 to the inkjet recording apparatus 2 via the valve system 23 are formed in the plate member 71. Of these four ink supply openings 70a to 70d, the ink supply opening 70a is circular in plan view and located at a substantially central portion of the plate member 71, and the other three ink supply openings 70b, 70c, 70d are elliptical in shape and are arranged in order in the circumferential direction around the circular ink supply opening 70 a. The ink chamber 16 and the communication chamber 30 communicate with the four ink supply openings 70a to 70d, thereby allowing the ink discharged from the ink supply openings 70a to 70d to be supplied to the inkjet recording apparatus 2 via the valve system 23.

Since the four ink supply openings 70a-70d are formed in the plate member 71 provided at the deeper portion 72a, the four ink supply openings 70a-70d are located at positions slightly higher than the deeper portion 72 a. Therefore, even if dust or the like generated when the main body casing 1a is formed remains in the ink chamber 16, such dust or the like remains at the deeper portion 72a and hardly flows out from the ink supply openings 70a to 70d located higher than the deeper portion 72 a. Thus, a filter for filtering ink discharged from the ink supply openings 70a-70d is not required.

On the bottom surface of the ink chamber 16, three projections 75 (ink guide portions) are formed, respectively, which project from the bottom surface 72 and extend from three side surfaces 73, 74 of the ink chamber 16 to the vicinity of the ink supply openings 70a to 70 d. The projections 75 are provided so that the projections 75 are directed toward the ink supply openings 70a-70d from three directions around the ink supply openings 70a-70 d. Therefore, even if the amount of ink remaining in the ink chamber 16 is small, the ink near the side surfaces 73, 74 of the ink chamber 16 can be guided to the ink supply openings 70a-70d by the three projections 75. In addition, the ends of the projections 75 opposite the ink supply openings 70a-70d connect the side surfaces 73, 74. Thus, when there is almost no ink in the ink chamber 16, even if ink is located at the edges 77 between the bottom surface 72 and the side surfaces 73, 74 (ink easily remains at these edges 77), it is possible to accurately guide the ink therein to the ink supply openings 70a-70 d.

Fig. 14 is a cross-sectional view of the cross-section VI in fig. 13. Fig. 15 is a cross-sectional view of cross-section VII in fig. 13. Fig. 16 is a cross-sectional view of cross-section VIII of fig. 13. Fig. 17 is a cross-sectional view of the cross-section IV of fig. 13. As shown in fig. 14-16, the radius of curvature R1, R2 at the edge 76 between each protrusion 75 and the bottom surface 72 is less than the radius of curvature R1 at the edge 77 between the side surfaces 73, 74 and the bottom surface 72. In other words, the curvature at edge 76 near ink supply openings 70a-70d is greater, which causes the edge to have a sharp shape. In addition, as shown in FIGS. 14 and 16, at the edge 76 between the protrusion 75 and the bottom surface 72, the radius of curvature r2 at a position 76b (position of cross section VIII) near the ink supply openings 70a-70d is smaller than the radius of curvature r1 at a position 76a (position of cross section VI) away from the ink supply openings 70a-70 d. That is, the curvature at edge 76 between protrusion 75 and bottom surface 72 is greater closer to ink supply openings 70a-70d, which causes the edge to have a sharp shape. Thus, the edge near ink supply openings 70a-70d applies a greater capillary force to the ink than the edge remote from ink supply openings 70a-70 d. Therefore, when the amount of ink remaining in the ink chamber 16 becomes small, the ink on the bottom surface 72 can be accurately guided to the ink supply openings 70a to 70 d. In this way, it is possible to prevent ink from sticking at positions away from the ink supply openings 70a to 70d, which would cause the ink to separate and remain at those positions if the ink were to stick there.

In addition, as shown in fig. 15 and 17, a radius of curvature R1 at an edge 77 extending horizontally between the side surfaces 73, 74 and the bottom surface 72 is smaller than a radius of curvature R2 at an edge 78 extending in the up-down direction between the two side surfaces 73, 74. Thus, the curvature at edge 77, which is closer to ink supply openings 70a-70d, is greater than the curvature at edge 78, which is further from ink supply openings 70a-70 d. In addition, the edge 78 extending up and down, the edge 77 extending horizontally, and the edge 76 between the bottom surface 72 and each protrusion 75 are connected together, and the radii of curvature of these three edges 76-78 become smaller (R1 < R1 < R2) the closer to the ink supply openings 70a-70d (the curvature becomes larger). Thus, as the ink surface in ink chamber 16 gradually decreases as ink is consumed, the ink can be accurately directed to ink supply openings 70a-70d from a higher position than ink supply openings 70a-70d using edges 76-78 of varying curvature. Therefore, the ink near the side surfaces 73, 74 of the ink chamber 16 can be accurately guided to the ink supply openings 70a-70 d.

The curvature is constant within either edge 77, 78 for the edges between the two surfaces forming the ink chamber 16 (e.g., edge 77 between the side surfaces 73, 74 and the bottom surface 72, edge 78 between the two side surfaces 73, 74). This only changes the curvature for each combination of two surfaces. Such a configuration in which the edge curvature is larger closer to the ink supply openings 70a-70d can be easily achieved by changing the curvature between the two surfaces for each combination of the two surfaces. In addition, as shown in fig. 15 and 17, at the edges 77, 78 between the two surfaces, the tangent planes 77A, 77B and 78A, 78B at the connecting portions of the two surfaces are parallel to the two surfaces, respectively. Therefore, the edges 77, 78 having a predetermined curvature are easily formed between the two surfaces.

According to the ink cartridge explained above, the edges 76-78 are the portions that form the ink chamber 16, and the curvature of the edges 76-78 is larger as they are closer to the ink supply openings 70a-70 d. Thus, as ink supply openings 70a-70d are approached, the shape of the edges changes from a gentle curvature to a sharp curvature, and the capillary force applied to the ink at the edges near ink supply openings 70a-70d increases. Therefore, ink can be prevented from sticking at the ink supply openings 70a to 70d and separating at the ink supply openings 70a to 70 d.

Modifications are explained below, wherein various changes are incorporated into the above-described embodiments. Elements having the same structure as those of the above-described embodiment are denoted by the same reference numerals and their description is omitted.

1) The shape of the projection of the ink guide portion is not limited to that in the above-described embodiment, but may be appropriately changed thereto. For example, as shown in fig. 18, projections 85 extending from the side surfaces 83, 84 of the ink chamber 81 toward the ink supply opening 80 may extend to the ink supply opening 80. In this case, the ink on the bottom surface 82 of the ink chamber 81 can be accurately guided to the ink supply opening 80 via the protrusion 85. In addition, the number and shape of the projections of the ink chamber may also be changed as appropriate.

2) The ink guide portion that guides the ink to the ink supply opening is not limited to the projection in the above-described embodiment. For example, as shown in fig. 19, the ink guiding portion may be constituted by a groove 89 formed on a bottom surface 88 of the ink chamber 87. Fig. 20A is a sectional view of the cross section X in fig. 19, and fig. 20B is a sectional view of the cross section XI in fig. 18. The edge 90 between the bottom surface 89a and the side surface 89B of the groove 89 has a structure such that the curvature at a position 90B (fig. 20B) close to the ink supply opening 90 is larger than the curvature at a position 90A (fig. 20A) far from the ink supply opening 90, whereby the edge 90 is formed into a sharp shape. Therefore, the ink on the bottom surface 88 can be guided to the ink supply opening 86 more accurately by the grooves 89.

3) Among the edges forming the internal structure of the ink chamber, not only those between the surfaces forming the ink chamber and those between the ink guide portion such as the projection and the bottom surface, but also other edges may have a structure with a curvature that is larger closer to the ink supply opening. For example, the rim may be formed by providing other projections or grooves, and the curvature of the rim is larger closer to the ink supply opening.

The structure of the ink cartridge 1 according to another embodiment of the present invention is described in detail below. Fig. 21 is a sectional view of the ink cartridge 1, and fig. 22 is a bottom view of the main body casing 1 a.

The ink cartridge 1 has an ink chamber 16 therein, and the ink chamber 16 forms a space for storing ink. The ink cartridge 1 is constituted by a main body casing 1a, a top 1b, and a cap 1f, the main body casing 1a having a bottom wall 1e and side walls 1c forming an ink chamber 16, the top 1b covering an open top surface of the main body casing 1a, and the cap 1f covering the bottom wall 1e of the main body casing 1 a. Two exposing holes 1fa, 1fb for exposing the valve systems 23, 24 described later to the mounting portion 3 are formed at the cap member 1 f. The ink cartridge 1 is formed by bonding the top 1b and the cap 1f to the main body casing 1 a. The top 1b, the main body casing 1a, and the cap 1f are formed of a resin material.

At one end (right side in fig. 21) of the cap 1f, a plate-shaped cap projecting portion 1d projecting to the main body case 1a side is formed, and an insertion portion 1g into which the cap projecting portion 1d is inserted is formed on the main body case 1 a. Therefore, since this structure provides the mounting body housing 1a and the cap 1f with the orientations, it is possible to prevent mounting errors and reduce the possibility of defective products.

A plurality of ink supply openings 21 are formed on the bottom wall 1 e. The plurality of ink supply openings 21 directly communicate with the communication chamber 30 to supply ink in the ink chamber 16. The communication chamber 30 is formed inside a cylindrical wall 30a, and the cylindrical wall 30a is formed integrally with the lower surface of the bottom wall 1e (the side of the ink chamber 16) and protrudes from the lower surface of the bottom wall 1 e. In addition, an air introduction opening 26 is formed in the bottom wall 1 e. The air introduction opening 26 directly communicates with the communication chamber 50 to introduce air into the ink chamber 16. The communication chamber 50 is formed inside a cylindrical wall 50a, and the cylindrical wall 50a is formed integrally with the lower surface of the bottom wall 1e (the side of the ink chamber 16) and protrudes from the lower surface of the bottom wall 1 e. When the ink cartridge 1 is mounted on the mounting portion 3, the ink extraction tube 12 and the air introduction tube 13 are inserted into the communication chamber 30 and the communication chamber 50, respectively.

A valve system 23 is provided in the communication chamber 30 to block communication between the inside and outside of the ink cartridge 1. A valve system 24 is provided in the communication chamber 50 to block communication between the inside and outside of the ink cartridge 1. The valve systems 23, 24 will be described in detail later.

The plurality of ink supply openings 21 allow communication between the communication chamber 30 and the ink chamber 16. The plurality of ink supply openings 21 are formed with three ellipses, and the three ellipses are arranged such that they substantially newly form a triangle (see fig. 22). Further, a shaft hole 1n is formed at the center position of the ink supply opening 21. A substantially umbrella-shaped check valve 60 is inserted through the axial hole 1 n. The check valve 60 is made of an elastic resin material having elasticity.

As shown in fig. 21, the check valve 60 faces the lower surface of the ink supply opening 21 and is formed of an elastic umbrella-shaped film portion 60b and a film portion 60c, the film portion 60c extending from the substantially central position of the film portion 60b to the ink chamber 16 through the shaft hole 1 n. The shaft portion 61c has a substantially spherical projecting portion 60a, the diameter of the projecting portion 60a is larger than the inner diameter of the shaft hole 1n, and the shaft hole 1n slidably supports the shaft portion 61c in the up/down direction between the film portion 60b and the projecting portion 60 a.

On the bottom wall 1e, a hollow cylindrical member 25 formed integrally with the bottom wall 1e is a hollow cylindrical shape extending in a direction from the bottom wall 1e toward the open top surface of the main body casing 1a (hereinafter referred to as "first direction"). The upper end opening 25a of the hollow cylindrical member 25 opens above the ink surface of the ink chamber 16. The hollow cylindrical member 25 is formed in a tapered shape, and its outer shape and the inner diameter of the internal flow passage 25b are gradually narrowed in a direction toward the upper side (a direction away from the later-described stopper member 100). The connecting portion 25c of the hollow cylindrical member 25 to the bottom wall 1e is formed in a shape gradually widening from the hollow cylindrical member 25 to the bottom wall 1 e. In addition, the cylindrical wall 50a of the communication chamber 50 is formed in a cylindrical shape, which is formed integrally with the hollow cylindrical member 25 from the lower end of the connecting portion 25c and passes through the bottom wall 1 e. Thus, the communication chamber 50 and the internal flow passage 25b of the hollow cylindrical member 25 are smoothly connected via the air introduction opening 26 and the tapered inner surface of the connecting portion 25 c. That is, one end of the hollow cylindrical member 25 communicates with the air introduction opening 26, and the other end communicates with the ink chamber 16. Thus, the internal flow passage 25b forms a flow passage for introducing air.

The opening 25a is inclined with respect to the first direction and inclined in a direction from the central axis of the ink cartridge 1 toward the side wall 1e and toward the side of the bottom wall 1 e. Therefore, the opening 25a has an elliptical substantially flat surface and an area larger than a cross-sectional area of the internal flow passage 25b perpendicular to the first direction.

The valve systems 23, 24 provided in the communication chambers 30, 50 are explained below.

The valve system 23 is provided with a support member 46 integrally made of a rubber elastic member, and a valve member 32 made of a resin material, the valve member 32 being structured so as to be able to contact with or separate from a valve seat portion 46 a. The support member 46 has a substantially cylindrical outer shape, which is constituted by a valve seat portion 46a, an urging portion 46b, a cylindrical portion 45, and an outer peripheral portion 45a, which are integrally formed, the valve seat portion 46a being located at a substantially middle portion in the direction of the central axis of the support member 46, the urging portion 46b being closer to the ink chamber 16 than the valve seat portion 46a, the cylindrical portion 45 extending from the valve seat portion 46a to the side opposite to the urging portion 46b, the outer peripheral portion 45a extending parallel to the outer periphery of the cylindrical portion 45 with a gap therebetween. The pushing portion 46b pushes the valve member 32 in a direction such that the valve member 32 contacts the valve seat portion 46a, and the valve member 32 is accommodated in the pushing portion 46 b.

The outer peripheral portion 45a has a connecting portion 33a projecting in the radial direction. The communication chamber 30 has a stepped surface 44, and the diameter of the outer stepped surface 44 is increased to accommodate the connection portion 33 a. In addition, a protruding projection 43 is formed on a surface of the connecting portion 33a contacting the step surface 44 and is formed in a ring shape. The main body housing 1a and the cap member 1f are coupled together in a state of being pressed and firmly holding the coupling portion 33a between the stepped surface 44 and the cap member 1f, so that it is possible to prevent ink from leaking out from between the main body housing 1a and the valve system 23.

The valve seat portion 46a has an opening 41 at the center thereof, and the opening 41 is formed in the central axis direction. The cylindrical portion 45 has an introduction passage 40, and when the ink cartridge 1 is mounted to the mounting portion 3, the ink extraction tube 12 is inserted into the introduction passage 40, and the cylindrical portion 45 is integrally connected to the valve seat portion 46a in such a manner that the introduction passage 40 communicates with the opening 41. The inner diameter of the introduction passage 40 is smaller than the outer diameter of the ink extraction tube 12 so that the cylindrical portion 45 is in close contact with the inserted ink extraction tube 12. The opening 41 is formed larger than the inner diameter of the introduction passage 40 and the outer diameter of the ink extraction tube 12. The introduction passage 40 is formed in a tapered shape at an end inserted into the ink extraction tube 12, and it gradually widens in an outward direction.

The annular groove 69 separates the cylindrical portion 45 from the outer peripheral portion 45a and deforms the cylindrical portion 45 relative to the outer peripheral portion 45a in a plane in which the cylindrical portion 45 is perpendicular to the central axis direction of the introducing passage 40. Thus, as the ink extraction tube 12 is inserted into the introduction passage 40, the diameter expansion of the cylindrical portion 45 becomes easy, and the sealability between the introduction passage 40 and the ink extraction tube 12 is increased, thereby preventing ink leakage. In addition, even if the ink extraction tube 12 is inserted obliquely into the introduction passage 40 or is not perfectly aligned when inserted, the ink extraction tube 12 can be inserted into the introduction passage 40 by the deformation of the cylindrical portion 45.

The urging portion 46b is formed by a side wall portion 36, an extending portion 37, and an opening 37a, the side wall portion 36 standing upright in a cylindrical shape from the periphery of the valve seat portion 46a on the ink chamber 16 side, the extending portion 37 connecting the side wall portions and extending inward so as to contact the valve member 32 on the ink chamber 16 side, the opening 37a being located at the center of the extending portion 37. The urging portion 46b urges the valve member 32 in a direction to bring the valve member 32 into contact with the valve seat portion 46a, using the elastic force of the side wall portion 36 and the extension portion 37. In a normal state, the valve element 32 is connected to the valve seat portion 46 a. However, when the ink extraction tube 12 is inserted into the introduction passage 40, the ink extraction tube 12 pushes up the valve member 32. Therefore, the side wall portion 36 is stretched and the extending portion 37 is inclined, so that a space in which ink can flow is formed between the valve element 32 and the valve seat portion 46 a.

The valve member 32 is provided with a bottom portion 57 and a valve side wall portion 51, the bottom portion 57 contacting the valve seat portion 46a of the support member 46, and the valve side wall portion 51 extending cylindrically and closer to the ink chamber 16 than the periphery of the bottom portion 57. The bottom portion 57 has an annular projecting member 39 projecting toward the valve seat portion 46a side, which is located radially inside of a communication passage 58 described later and outside of the opening 41. In a state where the valve element 32 is accommodated in the support member 46, the lower surface of the extension portion 37 of the pressing portion 46b presses the valve side wall portion 51, and the protruding piece 39 abuts against the upper surface of the valve seat portion 46a by elastic deformation of the valve seat portion 46a caused by pressure. Therefore, when the valve element 32 is accommodated in the support member 46, leakage of ink through the opening 41 and the introduction passage 40 can be prevented from occurring.

Communication passages 58 are formed from a position outside the projecting member 39 of the bottom portion 57 to the valve side wall portion 51, these communication passages 58 allow communication between the ink chamber 16 side and the valve seat portion 46a side of the valve member 32, and these communication passages 58 are circumferentially separated by a certain interval.

The valve system 24 is similar in structure to the valve system 23. The same reference numerals are used to designate the same components, and their description is omitted. In the valve system 24, the valve member 79 has a bottom portion 96, a valve side wall portion 97, a valve member projecting portion 98, and a communication passage 99, which have the same shape as the corresponding components of the valve member 32. A stopper 100 is further provided at a substantially central portion of the upper surface of the bottom portion 96, the stopper 100 projecting further toward the ink chamber 16 side than the valve side wall portion 97. The stopper member 100 has an outer diameter smaller than the inner diameter of the opening 37a of the pushing portion 37 and passes through the opening 37a with a certain clearance left therebetween. In addition, with the stopper 100, the outer diameter D1 at the upper end 100a opposite to the bottom portion 96 of the valve member 79 is slightly smaller than the inner diameter D2 at the lower end side of the internal flow passage 25b of the hollow cylindrical member 25, and the outer diameter D1 is larger than the inner diameter D3 at the upper portion side of the internal flow passage 25b (see fig. 23A). The internal flow passage 25b is formed to be slightly tapered from an inner diameter D2 at the lower end to an inner diameter D3 at the upper portion. Thus, when the upper end 100a of the stopper 100 is engaged, the upper end 100a frictionally engages the inside of the internal flow passage 41 and is in an "occluded" condition. The elastic force applied to push the pushing portion 46b of the valve member 79 cannot release such a state. The upper end 100a of the obstruction 100 closes the internal flow passage 25b very tightly and obstructs the flow of air. The upper end 100a of the blocking member 100 is formed in a tapered shape in which the outer diameter decreases in the direction of the inner flow passage 25 b.

When the ink cartridge 1 is mounted to the mounting portion 3, the ink extraction tube 12 and the air introduction tube 13 are inserted into the corresponding introduction passages 40 while expanding the diameter of the cylindrical portion 45 and contacting the respective valve members 32, 79 of the bottom portions 57, 96. Subsequently, when the ink cartridge 1 is further pushed, the respective valve members 32, 79 are pressed in the direction toward the ink chamber 16 and the valve members 32, 79 are separated from the valve seat portions 46 a. Thus, an introduction passage for introducing air into the inside of the ink cartridge and a supply passage for supplying ink to the outside of the ink cartridge 1 are formed. Since the ink cartridge 1 is in a depressurized state at the time of packaging, a flow from the ink extraction tube 12 to the ink chamber 16 and a flow from the air introduction tube 13 to the ink chamber 16 are created. However, the backflow of the ink remaining in the flow passage between the ink extraction tube 12 and the recording head 7 can be prevented by the check valve 60, and thus the air rapidly flows from the air introduction tube 13 into the upper portion of the ink chamber 16 via the hollow cylindrical member 25. Therefore, even if the ink cartridge 1 drops during transportation so that the ink enters the hollow cylindrical member 25 or the communication chamber 50, the ink returns to the ink chamber 16. At this time, since the communication chamber 50 smoothly connects the internal flow passage 25b of the hollow cylindrical member 25 via the tapered inner surface of the connecting portion 25c, the ink flows quickly.

If the valve element 32 on the ink supply side is opened earlier than the valve element 79 on the air introduction side due to the inclination of the ink cartridge 1 during the process of mounting the ink cartridge 1 to the mounting portion 3, a quick return of ink from the ink extraction tube 12 to the ink chamber 16 occurs. But is prevented because it causes check valve 60 to close ink supply opening 21. It is preferable to appropriately set the lengths of the ink extraction tube 12 and the air introduction tube 13 so that the valve system 24 on the air introduction side can be accurately opened earlier than the valve system 23 on the ink supply side, thereby preventing rapid backflow of ink from the ink extraction tube 12.

Under normal conditions, the film portion 60d of the check valve 60 descends to a position away from the ink supply opening 21 due to its own weight. As the ink from the ink chamber 16 flows, air is supplied from the air introduction tube 13 to the upper portion of the ink chamber 16.

The operation of the valve element 79 is explained below with reference to fig. 23A and 23B. Fig. 23A shows a state where the ink cartridge 1 is properly mounted to the mounting portion 3. As described above, the air introduction pipe 13 pushes up the valve member 79, thereby forming an introduction passage for introducing air. The distance (amount of movement) by which the valve member 79 is separated from the valve seat portion 46a at this time is substantially constant. In addition, in order to ensure the air passage, the valve member 79 is positioned such that a predetermined gap exists between the front end 100a of the blocking member 100 and the internal flow passage 25 b.

Fig. 23B shows a case where the lever a accidentally pushes the valve member 79 and the valve member 79 moves a longer distance than when the ink cartridge 1 is properly mounted (shown in the state of fig. 23A). In this state, the front end 100a of the blocking member 100 of the valve member 79 enters the internal flow passage 25b and closes the flow passage of the internal flow passage 25b, and the blocking member 100 is held in the internal flow passage 25b under the above-described frictional engagement action.

As described above, in the ink cartridge 1 described above, the stopper member 100 closes the inner flow passage 25b if the valve member 79 is accidentally moved a further distance than if the ink cartridge 1 is properly installed. Therefore, even if the communication chamber 50 is opened, air pressure does not act on the ink, and the possibility of ink leaking out of the communication chamber 50 is reduced to a minimum.

In addition, if the valve member 79 is pushed to move to a position farther than the predetermined distance as described above, the amount of extension of the pressing portion 46B of the support member 46 is larger than when the ink cartridge 1 is properly mounted (see fig. 23B). Therefore, the pushing portion 46b may be damaged, or the valve member 79 may be ejected from the inside of the pushing portion 46 b. However, since the amount of movement of the blocking member 100 is restricted by the inner flow passage 25b, damage to the pushing portion 46b or ejection of the valve member 79 from the inside of the pushing portion 46b can be accurately avoided.

In addition, the internal flow path 25b is formed in a tapered shape in which its inner diameter is gradually narrowed in a direction toward the upper side of the ink cartridge. The front end 100a of the obstructing member 100 is also formed in a tapered shape in which its outer diameter narrows in a direction toward the inner flow passage 25 b. Therefore, even if the inclination occurs in the direction of pushing the valve member 79, the blocking member 100 can be accurately inserted into the inner flow passage 25 b.

The structure of the ink cartridge 1 according to another embodiment of the present invention is described in detail below. Fig. 24 is a sectional view of the ink cartridge 1. The same reference numerals are used to designate the same components as those of the previous embodiment, and their description is omitted.

Unlike the embodiment of fig. 21, the support 46 does not have an annular groove between the cylindrical portion 45 and the outer peripheral portion 45 a. However, in combination with the valve member 32 and the ink extraction tube 12, each of the other components has a function similar to that of the embodiment of fig. 21.

In this embodiment, an annular seal portion 101 is formed around the ring 40 at a position closer to the mounting portion 3 side than to the outer peripheral portion 45a side. The valve member 79 is further provided with a generally shaft-shaped operating member 102 extending to the mounting portion 3 side through the opening 40 formed in the bottom portion 96.

Similar to the embodiment of fig. 2A, the mounting portion 3 is constituted by a base portion 3a and guide portions 3b standing upright from both sides of the base portion 3a, and it is provided with an ink extraction tube 12 projecting therefrom. A recessed portion 103 is formed on a part of the base portion 3a connected to the ink extraction tube 12. In the recessed portion 103, a porous member 104 capable of absorbing ink and having flexibility is provided. The porous member 104 is larger in size than the exposure hole 1fa of the cap member 1 f. In addition, instead of the air introduction pipe 13, an air introduction passage 105 communicating with the atmosphere is formed. At its peripheral portion, a recess 106 is formed whose size is larger than that of the exposure hole 1fb of the cap member 1 f.

Similar to the embodiment of fig. 2A, when the ink cartridge 1 is mounted to the mounting portion 3, the ink extraction tube 12 enters the introduction passage 40 while expanding the cylindrical portion 45, and pushes up the valve member 32 of the valve system 23 toward the ink chamber 16 to form an ink supply passage. When the mounting of the ink cartridge 1 to the mounting portion 3 is completed, the protruding portion surrounding the exposure hole 1fa contacts the porous member 104. Therefore, even if ink leaks from the valve system 23 or ink sticking to the ink extraction tube 12 drops when the ink cartridge 1 is repeatedly attached and detached, the porous member 104 can absorb the ink. Therefore, the possibility of contamination of the surrounding environment with ink can be reduced to a minimum.

In addition, on the air introduction side, the seal portion 101 closely contacts the recess portion 106 of the base portion 3a by contact and elastic deformation. Thus, the inside of the sealing portion 101 is sealed with respect to the outside. At this time, the operation member 102 contacts the bottom of the recess 106 at a position offset from the air introduction passage 105. When the mounting of the ink cartridge 1 is continued, the valve member 79 is pushed toward the ink chamber 16 to form an air introduction passage similar to that in the embodiment of fig. 2A.

In the ink cartridge 1 according to this embodiment, the stopper 100 has the same shape as the ink cartridge 1 in the embodiment of fig. 21 in structure, and provides effects similar to those of the first embodiment.

It will be understood that various modifications can be made. For example, in the above-described embodiment, the stopper member 100 and the valve member 79 are integrally formed, respectively. However, the valve member and the blocking member may be separate bodies or they may have a structure to connect them or to interlock their operation.

In addition, a hollow cylindrical member 25 rises from the bottom wall 1e in the first direction and is formed integrally with the bottom wall 1 e. The upper end opening 25a of the hollow cylindrical member 25 opens above the ink surface in the ink chamber 16, and the opposite end of the internal flow passage 25b connects the communication chamber 50.

The contact portion 25c between the hollow cylindrical member 25 and the bottom wall 1e is formed in a shape gradually expanding from the hollow cylindrical member 25 toward the bottom wall 1 e. The contact portion between the hollow cylindrical member 25 and the communication chamber 50 is smoothly formed without any stepped surface.

The upper end opening 25a is inclined with respect to the first direction and inclined in a direction from the central axis of the ink cartridge 1 toward the side wall 1c and toward the bottom wall 1 e. Therefore, since the upper-end opening 25a has a substantially elliptical flat surface, the area of the upper-end opening 25a is larger than the cross-sectional area of the internal flow passage 25b in the direction perpendicular to the first direction.

As for the peripheral wall 27 of the hollow cylindrical member 25, the topmost surface 25d thereof is a substantially flat surface substantially parallel to the bottom wall 1 e. And the end surface of the peripheral wall 27 is formed as a surface inclined along the outer periphery of the upper end opening 25a except for the topmost surface 25 d.

The diameter of the upper end opening 25a in the oblique direction (i.e., major axis) is about 1mm, preferably 2mm or more. This is because the surface tension of the ink used in this embodiment is 30mN/m to 45mN/m when 25C, so that even if the ink sticks to the upper end opening 25a, a meniscus is hardly formed, or even if a meniscus is formed, it is easily broken with the introduction of air.

Preferably, the inner diameter of the internal flow channel 25b is about 0.8mm or greater. This is because if the inner diameter of the internal flow channel 25b is less than 0.8mm, the ink easily forms a meniscus in the direction of closing the internal flow channel 25 b. If the inner diameter of the internal flow channel 25b is about 0.8mm or more, it is difficult to form a meniscus, or even if a meniscus is formed, it is easily broken with the introduction of air. In addition, even if ink adheres along the inner surface of the internal flow path 25b, it is possible to ensure that the flow path has a sufficient cross-sectional area so as not to significantly increase the resistance to the introduction of air.

Since the hollow cylindrical member 25 is integrally formed with the main body housing 1a and the top surface of the main body housing 1a is opened, the main body housing 1a is easily manufactured using a molding die, which reduces the manufacturing cost. In addition, the assembly process can be eliminated, thereby increasing the effectiveness of the operation. In addition, it is possible to avoid occurrence of an unfavorable effect that air cannot be correctly introduced from the connecting portion 25c due to the flow of ink in the internal flow path 25 b.

After manufacturing, before the user mounts the ink cartridge 1 to the inkjet recording apparatus 2, when the ink cartridge 1 is tilted or dropped, ink may stick to the open end of the hollow cylindrical member 25 or ink may enter the inside thereof. As described above, in the depressurized state, a large amount of ink in the hollow cylindrical member 25 returns to the ink chamber 16 due to the action of the air rapidly flowing into the ink cartridge 1. However, if ink remains in the hollow cylindrical member 25 at this time or if the user subsequently removes the ink cartridge 1 from the mounting portion 3 and tilts the ink cartridge 1 or drops the ink cartridge 1, the internal flow passage of the hollow cylindrical member 25 may be blocked. However, the upper end opening 25a of the hollow cylindrical member 25 is formed to be inclined with respect to the first direction and to have an area larger than the cross-sectional area of the internal flow passage 25b in the direction perpendicular to the first direction. The possibility of the ink forming a meniscus in the upper end opening 25a can be reduced. In addition, even if a meniscus is formed, the introduction of air can easily cause it to break. In addition, the inner diameter of the internal flow channel 25b has a size such that a meniscus is not formed in a direction blocking the internal flow channel 25 b. Therefore, air is correctly introduced without causing fluctuation, and ink supply to the recording head 7 can be smoothly completed, so that uniform ink discharge can be maintained.

A modified example of the upper end opening 25A of the hollow cylindrical member 25 is explained below with reference to fig. 25A to 26B.

As shown in fig. 25A and 25B, the upper end portion of the hollow cylindrical member 25 may be formed in a stepped shape. The upper end opening 25a may be constituted by semicircular planes 25aa, 25ac, which are substantially parallel to the bottom wall and at different heights, and by a rectangular plane 25ab, which is substantially perpendicular to the bottom wall 1e, and the upper end opening 25a has a non-circular periphery.

As shown in fig. 26A and 26B, the upper end opening 25a of the air introduction member 25 may be formed as an inclined surface with respect to the first direction, and the protruding portion 244a may protrude from one side of the front end opening 25a in the first direction. Therefore, the front end opening 25a is formed in a substantially elliptical shape and the outer periphery thereof is constituted by flat surfaces 245a, 245b and a vertical plane 241a, wherein the flat surface 245a is the upper end of the protruding portion 244a, the flat surface 245b includes most of the front end opening 25a, and the vertical plane 241a connects the flat surfaces 245a, 245 b.

In the modified example described above, the inner diameter of the internal flow passage 25b of the air introduction member 25 is equal to or greater than 0.8 mm. The air introduction member 25 is formed not only such that the area of the opening 25a is larger than the cross-sectional area of the internal flow passage in the direction perpendicular to the first direction, but also such that the surface forming the outer periphery of the opening is formed with three planes different from each other. Therefore, the possibility that ink forms a meniscus in the upper end opening 25a can be reduced, and therefore effects similar to those of the above-described embodiment can be provided.

It will be understood that various modifications can be made. For example, in the above-described embodiment, the opening of the hollow cylindrical member 25 may be formed with two planes intersecting in the diagonal direction at an angle different from the first direction, or may be formed in a non-circular shape with a part of a circle cut off.

In addition, a hollow cylindrical member 25 is formed on the bottom wall 1e, which is integrally formed with the bottom wall 1e and rises from the bottom wall 1e in the first direction toward the top surface of the main body casing 1 a. The front end opening 25a of the air introduction member opens above the ink surface in the ink chamber 16. The outer shape of the hollow cylindrical member 25 and the internal flow passage 25b are formed in a tapered shape whose diameter is gradually reduced toward the upper side. The connecting portion connecting the hollow cylindrical member 25 and the bottom wall 1e is formed in a shape gradually expanding from the top of the hollow cylindrical member 25 toward the bottom wall 1 e. Further, the cylindrical wall 50a of the communication chamber 50 is cylindrical, is formed integrally with the hollow cylindrical member 25, and is located at the lower end of the connecting portion 25c, passing through the bottom wall 1 e. Thus, the communication chamber 50 and the internal flow passage 25b of the hollow cylindrical member 25 are smoothly and continuously formed by the tapered inner surface of the connecting portion 25 c. In addition, the connecting portion 25c increases the strength of the connecting point of the hollow cylindrical member 25 and the bottom wall 1e, and can prevent the hollow cylindrical member 25 from being deformed at the time of molding or due to environmental changes.

As described above, the main body casing 1a of the ink cartridge 1 described above has a shape such that the top surface thereof is open. The hollow cylindrical member 25 is formed integrally with the bottom wall 1e and is formed in a shape gradually expanding from the front end opening 25a toward the bottom wall 1 e. Therefore, the main body housing 1a is easily manufactured using the molding die, which reduces the manufacturing cost. In addition, since the hollow cylindrical member 25 and the main body housing 1a are integrally formed, an assembling process can be omitted, and the operation efficiency can be improved. In addition, it is possible to avoid the occurrence of an unfavorable effect that air cannot be correctly introduced from the connecting portion 25c between the hollow cylindrical member 25 and the main body casing 1a due to the ink entering the internal flow passage 25b of the hollow cylindrical member 25.

According to a representative aspect of the present invention, when the air introducing side seal and the ink supplying side seal are opened while the ink cartridge is mounted to the recording apparatus main body, it is possible to prevent the ink from flowing back from the ink supplying opening to the ink chamber in a depressurized state. In addition, it is possible to prevent deterioration of the ink degassing state due to mixing of the ink on the recording apparatus side with the degassed ink in the ink cartridge. In addition, it is possible to prevent damage to the ink meniscus inside the recording head nozzles, and thereby reduce defective ink ejection that occurs in the recording head. This enables excellent recording quality to be maintained.

According to a representative aspect of the present invention, since the two sealing members can allow communication by mounting the ink cartridge from one direction, it becomes easy to mount the ink cartridge to the recording apparatus main body. In addition, as described above, even if any one of the sealing members is opened first due to the inclination of the ink cartridge during the mounting process, it is possible to have an effect of preventing the backflow of ink.

According to a representative aspect of the present invention, a small amount of reflow can be tolerated, and thus a drastic change in pressure on the recording head side can be prevented. That is, with a structure capable of closing the valve in a normal state and opening the valve only at the time of ink supply, when the pressure on the recording side changes and increases due to the movement of the ink cartridge, the ink does not have a position where it can leak out, and the pressure on the recording side increases, so that normal ink discharge is avoided. Therefore, by simply blocking the ink supply opening with the check valve and opening the ink supply opening in a normal state when ink flows from the area outside the ink supply opening to the ink chamber, a small amount of backflow can be tolerated and such a phenomenon is prevented.

According to a representative aspect of the present invention, the introduction of air and the supply of ink are completely separated, so that an effect is achieved in which air is not mixed into the supply of ink.

According to a representative aspect of the present invention, there are achieved effects that the check valve can be simply formed at low cost as described above, and that pressure fluctuation on the recording head side can be prevented and that backflow can be accurately prevented when backflow occurs.

According to a representative aspect of the present invention, the seal member can be formed with a simple structure, and the mounting of the ink cartridge to the main body of the recording apparatus becomes easy.

In japanese laid-open patent application No. h9-85963, there is an ink jet recording apparatus having a structure that enables an ink container (referred to as an "ink cartridge") to be attached to or detached from a holder (mounting portion). A projection that opens an opening of the ink cartridge is formed on the holder, and the projection is provided with a through hole that enables ink to flow from the valve to the ink reservoir. When the ink cartridge is mounted to the holder, the projection opens the valve, and ink in the ink cartridge flows through the opening to the ink reservoir.

However, when the mounting portion to which the ink cartridge is mounted is provided with the protruding portion, and when the opening of the ink cartridge is opened by the protruding portion, the opening must be accurately disposed at the position where the protruding portion connects to the ink cartridge. In addition, if the shape of the protruding portion is not accurately measured, the ink cartridge may not be smoothly mounted, and/or the ink may leak or evaporate.

Particularly with the ink cartridge in japanese laid-open patent application No. h9-85963 described above, provided with the ink supply opening and the air introduction opening, it is necessary to seal the ink supply opening and the flow passage on the side of the mounting portion and make them correspond precisely so that the ink does not leak. In addition, the two projecting portions must correspond precisely to the ink supply opening and the air introduction opening. Therefore, the ink cartridge must be manufactured with very high precision.

In view of the above-described problems, embodiments of the present invention provide an ink cartridge, a valve system, and an inkjet recording apparatus with which the ink cartridge can be easily mounted to the inkjet recording apparatus and the manufacturing thereof is simple.

An ink cartridge according to a representative aspect of the present invention is detachably mountable to a mounting portion of a recording apparatus. The ink cartridge is provided with an ink chamber which is capable of communicating with a flow passage provided on the mounting portion via an opening, and has a valve member which opens and closes the opening to allow the ink chamber to communicate with or be closed with respect to the outside, and an operating member provided outside the ink cartridge and protruding from the valve member. When the ink cartridge is mounted to the mounting portion, the valve member opens the opening with the operating member in contact with the mounting portion so that the ink chamber and the flow passage communicate through the opening.

The ink cartridge according to a representative aspect of the present invention further has a valve seat portion with which the valve element is in contact, and urging means for urging the valve element in a direction to contact the valve seat portion. The valve seat portion has an opening at its substantially center and contacts the valve member at an outer periphery of the opening, and the operating member protrudes from the valve member to the outside through the opening.

In the ink cartridge according to a representative aspect of the present invention, the urging means is raised from an outer periphery of the valve seat portion and surrounds the valve element, and is formed integrally with the valve seat portion in an inwardly extending shape with a rubber elastic material so as to contact the valve element on a side opposite to the valve seat portion.

The ink cartridge according to a representative aspect of the present invention further has a sealing member that surrounds the operation member and that closely contacts the mounting portion when the ink cartridge is mounted to the mounting portion, thereby forming a communication passage that provides communication between the ink chamber and the flow passage through the opening.

In the ink cartridge according to a representative aspect of the present invention, the sealing means closely contacts the mounting portion and forms a communication passage allowing the ink chamber and the flow passage to communicate through the opening when the ink cartridge is mounted to the mounting portion, rises from the valve seat portion on the side opposite to the valve member while surrounding the opening, and is integrally formed with the valve seat portion with a rubber elastic material.

An ink cartridge according to a representative aspect of the present invention has an ink chamber that stores ink and is detachably mounted to a mounting portion of a recording apparatus. The ink cartridge includes an air introduction opening which communicates with the ink chamber and is opened for introducing air into the ink chamber; a first sealing means which seals the air introduction opening in a normal state and which opens the ink supply opening when the ink cartridge is mounted to the mounting portion, an ink supply opening which communicates with the ink chamber and which opens for supplying ink in the ink chamber to the outside; and a second sealing means which seals the ink supply opening in a normal state and which opens the ink supply opening when the ink cartridge is mounted to the mounting portion. At least one of the first and second sealing means is a valve means including a valve seat portion and a valve member movable relative to the valve seat portion, the valve member having an operating member projecting to the outside of the ink cartridge, and being structured such that the operating member contacts the mounting portion when the ink cartridge is mounted to the mounting portion to thereby separate the valve member from the valve seat portion.

In the ink cartridge according to a representative aspect of the present invention, the air introduction opening and the ink supply opening are formed side by side on one side of the ink chamber, and the first and second sealing members are opened when the ink cartridge is mounted to the mounting portion.

In the ink cartridge according to a representative aspect of the present invention, the first sealing means is a valve means including a first valve seat portion and a first valve member movable relative to the first valve seat portion, the first valve member having an operating member projecting to an outside of the ink cartridge, and is structured such that the operating member contacts the mounting portion when the ink cartridge is mounted to the mounting portion to separate the valve member from the valve seat portion. The second sealing means is a valve means including a second valve seat portion and a second valve member movable relative to the second valve seat portion, the second sealing means being constructed to provide the mounting portion with a protruding hollow member that contacts the second valve member when the ink cartridge is mounted to the mounting portion to thereby separate the second valve member from the second valve seat portion.

A valve system according to a representative aspect of the present invention has a valve member which is movable and has a valve portion and an operating member, and a support member which is integrally made of a rubber elastic material, the support member having a valve seat portion which has an opening at a substantially central portion and contacts the valve portion at a periphery of the opening, and a pushing portion which rises from an outer periphery of the valve seat portion while surrounding the valve portion and extends inward so as to contact the valve portion opposite to the valve seat portion, the pushing portion pushing the valve portion in a direction such that the valve portion contacts the valve seat portion. The operating member of the valve member projects outwardly through the opening of the valve seat portion. The valve portion of the valve member is held between the valve seat portion and the urging portion of the support member. When the operating member is operated and the valve portion is moved against the urging of the urging portion, the valve portion is separated from the valve seat portion to open the opening.

In the ink cartridge according to a representative aspect of the present invention, the support member further includes a sealing means around the opening and the outer periphery of the operation member.

An ink jet recording apparatus according to a representative aspect of the present invention includes a recording head which performs recording by discharging ink, an ink cartridge having an ink chamber which stores the ink, an ink supply opening which supplies the ink to the recording head, and an air introduction opening which introduces air into the ink chamber, and a mounting portion which detachably mounts the ink cartridge, the mounting portion having an extraction portion which supplies the ink sucked from the ink cartridge to the recording head, and an air supply portion which supplies the air into the ink cartridge. When the ink cartridge is mounted to the mounting portion, the ink supply opening and the air introduction opening are positioned to correspond to the extraction portion and the air supply portion, respectively. The ink cartridge has first and second sealing means that respectively seal the ink supply opening and the air introduction opening and open the air introduction opening when the ink cartridge is mounted to the mounting portion. At least one of the first and second sealing means is a valve means including a valve seat portion and a valve member movable relative to the valve seat portion, the valve member having an operating member projecting to the outside of the ink cartridge, the operating member contacting the mounting portion when the ink cartridge is mounted on the mounting portion to thereby separate the valve member from the valve seat portion and communicating the ink supply opening and the extraction portion or the air introduction opening and the air supply portion. A sealing device is provided between the ink cartridge and the mounting portion, the sealing device surrounding the operating member and closing the ink supply opening and one of the extraction portion and the air introduction opening and the air supply portion from outside when the ink cartridge is mounted on the mounting portion to achieve a communicating state.

In the ink cartridge according to a representative aspect of the present invention, the other of the first and second sealing means is a valve means including a second valve seat portion and a second valve member movable relative to the second valve seat portion. The hollow member in the mounting portion sets the other of the extracting portion and the air supply portion in the communication state in the extended state, and the hollow member is inserted into the second valve seat portion to separate the second valve member from the valve seat portion, resulting in communication of the ink supply opening and the other set of the extracting portion and the air introduction opening and the air supply portion.

An ink cartridge according to a representative aspect of the present invention has a valve member that opens and closes an opening to allow an ink chamber to communicate with and be isolated from the outside, and an operating member that extends from the valve member to the outside of the ink chamber. When the ink cartridge is mounted to the mounting portion, the valve member opens the opening with the operating member in contact with the mounting portion so that the ink chamber and the flow passage communicate through the opening.

In addition, it is not necessary to provide a projecting portion to open the opening of the valve element at the mounting portion of the ink jet recording apparatus. Thus, an effect is achieved in which positioning of the ink cartridge and the mounting portion becomes simple when the ink cartridge is mounted to the mounting portion.

In addition, the ink cartridge of a representative aspect of the present invention further includes a valve seat portion with which the valve element contacts, and an urging device that urges the valve element in a direction such that the valve element contacts the valve seat portion. The valve seat portion has an opening at a substantially central position thereof and contacts the valve member at a periphery of the opening, and the operating member projects from the valve member to the outside through the opening. Therefore, when the ink cartridge is detached from the ink jet recording apparatus, the valve member contacts the valve seat portion with the pressing portion, and the ink is prevented from leaving or volatilizing through the opening.

Further, it is possible to achieve an effect that the valve can be opened by lifting the valve member in unison and separating the valve member from the valve seat portion by the operating member when the ink cartridge is mounted to the ink jet recording apparatus.

Further, according to the ink cartridge of the representative aspect of the present invention, the urging means rises from the periphery of the valve seat portion and surrounds the valve element, and the urging means is integrally formed with the valve seat portion in an inwardly extending shape so as to contact the valve element on the side opposite to the valve seat portion with a rubber elastic material. Thus, there is no need for a complicated operation procedure in which the urging means is connected such that it urges the valve member in the region in which the valve member is located. Thus having the effect of reducing the manufacturing cost of the ink cartridge.

In addition, the ink cartridge according to a representative aspect of the present invention further has a sealing device that surrounds the operation member and that closely contacts the mounting portion when the ink cartridge is mounted to the mounting portion, thereby forming a communication passage that provides communication between the ink chamber and the flow passage through the opening. Therefore, the ink can be prevented from leaving or volatilizing through the opening.

In addition, in the ink cartridge according to a representative aspect of the present invention, the sealing means rises from the valve seat portion on the side opposite to the valve member while surrounding the opening and is integrally formed with the valve seat portion with a rubber elastic material. Therefore, such complicated operation procedures of attaching the sealing device to the valve seat portion are not required. Thus, the effect of reducing the manufacturing cost of the ink cartridge is achieved.

The ink cartridge according to a representative aspect of the present invention is capable of opening the ink supply opening and the air introduction opening when the ink cartridge is mounted to the mounting portion and thereby introducing air into the ink cartridge while supplying ink to the recording apparatus. Further, at least one of the first and second sealing means is a valve means comprising a valve seat portion and a valve member movable relative to the valve seat portion. The valve member has an operating member protruding to the outside of the ink cartridge, and is structured such that when the ink cartridge is mounted on the mounting portion, the operating member contacts the mounting portion to separate the valve member from the valve seat portion. When the mounting portion is provided with the operation member projecting in correspondence with the first and second sealing means, it is necessary to seal it to prevent ink leakage and manufacture it so as to be able to accurately maintain the mutual positional relationship between the two projecting operation members and the mutual positional relationship between the ink supply opening and the air introduction opening. However, the present invention achieves the effect that the ink cartridge can be easily mounted to the mounting portion while the ink cartridge can be easily manufactured without requiring a very precise positional relationship.

In addition, in the ink cartridge according to a representative aspect of the present invention, the air introduction opening and the ink supply opening are formed side by side on one side of the ink chamber, and the first and second sealing members are opened when the ink cartridge is mounted to the mounting portion. Therefore, both the sealing means can be opened by simply moving the ink cartridge in the direction of the mounting portion, thereby providing better operability.

In addition to the above effects, in the ink cartridge according to a representative aspect of the present invention, the first valve device has an operating member that protrudes to the outside of the ink cartridge and is structured such that the operating member contacts the mounting portion when the ink cartridge is mounted to the mounting portion to separate the valve member from the valve seat portion. The second valve device is constructed such that the mounting portion is provided with an extended hollow member which contacts the second valve member to separate the second valve member from the second valve seat portion. When the ink cartridge is mounted to the mounting portion, it is necessary to accurately position the second valve device at the position of the hollow member provided in the mounting portion. However, the position of the first valve device does not need to be accurately positioned, and therefore, there are effects that the ink cartridge can be simply manufactured and the mounting of the ink cartridge to the mounting portion becomes simple.

According to a valve system according to a representative aspect of the present invention, a valve member, which is movable and has a valve portion and an operating member, a valve seat portion, which contacts the valve portion, and an urging portion, which rises from an outer periphery of the valve seat portion while surrounding the valve portion and extends inward so as to contact the valve portion opposite to the valve seat portion, are integrally formed of a rubber elastic material, and the urging portion urges the valve portion in a direction such that the valve portion contacts the valve seat portion. Thus, there is no need for a complicated operation procedure in which the urging means is connected such that it urges the valve member in the region in which the valve member is located. Thus having the effect of reducing the manufacturing cost of the ink cartridge.

In addition, the valve member has an opening in a substantially central portion and has a valve portion that contacts the valve seat portion at the periphery of the opening and the operation member. Thus, there is achieved an effect that the operation of the operating member can raise the valves in unison, opening the valves by separating the valve portion and the valve seat portion.

Further, in an ink cartridge according to a representative aspect of the present invention, the support member includes a sealing means around the opening and the periphery of the operation member. Therefore, there is an effect of preventing the fluid flowing to the valve system from leaking to the outside.

In the ink jet recording apparatus of a representative aspect of the present invention, when the ink cartridge is mounted to the mounting portion, the ink supply opening and the air introduction opening are opened, and air is introduced into the ink cartridge while supplying ink to the recording apparatus. Further, at least one of the first and second sealing means is a valve means including a valve member having an operating member projecting to the outside of the ink cartridge, the operating member contacting the mounting portion when the ink cartridge is mounted so as to separate the valve member from the valve seat portion and communicating the ink supply opening and the extraction portion. There is an effect that the ink cartridge can be simply manufactured, the mutual positional relationship between the ink supply opening and the air introduction opening of the ink cartridge or the mutual positional relationship between the extraction portion and the air supply portion of the mounting portion does not need to have high accuracy, and therefore the mounting of the ink cartridge to the mounting portion can be easily achieved.

Further, a sealing device is provided between the ink cartridge and the mounting portion, the sealing device surrounding the operating member and closing the ink supply opening and one set of the extraction portion and the air introduction opening and the air supply portion from outside when the ink cartridge is mounted to the mounting portion to achieve the communicating state. And thus has an effect of preventing ink from leaking to the outside or volatilizing.

Further, in the ink cartridge of the representative aspect of the present invention, the other of the first and second sealing means is a valve means including a second valve seat portion and a second valve member movable relative to the second valve seat portion. The hollow member in the mounting portion provides the other of the extracting portion and the air supplying portion in the communicating state in the extended state. Thus, there is an effect that, when the ink cartridge is mounted to the mounting portion, the insertion of the hollow member into the second valve seat portion separates the second valve member from the valve seat portion, resulting in communication of the ink supply opening and the other of the extraction portion and the air introduction opening and the air supply portion.

In addition, when the protruding hollow members are provided at both the ink extracting portion and the air supplying portion of the mounting portion, the distance between the two hollow members requires a very strict tolerance. However, this problem can be solved by providing one of them as a hollow member extending from the mounting portion and providing the operating member at the other. Therefore, there is an effect that the manufacturing cost of the ink jet apparatus can be reduced.

The ink cartridge has an ink chamber filled with ink. When the ink cartridge is mounted in a recording apparatus such as an ink jet printer, ink is supplied from the ink chamber to the recording apparatus. Depending on the internal structure of the ink chamber and the viscosity of the ink, the ink may partially remain inside the ink chamber. Therefore, an ink cartridge capable of preventing such residual ink from occurring is proposed in japanese laid-open patent application No.2000-71471, which is provided with a groove for discharging ink around a prism for detecting the amount of residual ink. In such an ink cartridge, the ink around the prism is gradually discharged by using the groove so that the ink is hardly left on the surface of the prism, and it is possible to prevent an error in detecting the amount of ink when there is only a small amount of ink in the ink chamber.

However, in the ink cartridge described above, if the curvature of the groove formed in the ink chamber for discharging ink is constant, the magnitude of the capillary force applied from the groove to the ink at a position close to the ink supply portion and a position far from the ink supply portion is substantially the same, and the ink is supplied to the recording apparatus at the ink supply portion. Therefore, when the amount of ink remaining in the ink chamber becomes small, the ink separates to a position away from the ink supply portion, so that the ink remains in the ink chamber. Thus, the ink in the ink chamber cannot be used up.

The disclosed embodiments provide an ink cartridge that can more accurately prevent ink from remaining in an ink chamber.

An ink cartridge of a representative aspect of the present invention is an ink cartridge including an ink chamber and an ink supply opening that supplies ink in the ink chamber to a recording apparatus, wherein a curvature of at least a part of a plurality of edges forming an internal shape of the ink chamber is larger closer to the ink supply opening.

In such an ink cartridge, ink in the ink chamber is supplied from the ink supply opening to the recording apparatus. The curvature of at least a part of the plurality of edges forming the internal shape of the ink chamber (such as the edge between the surfaces forming the ink chamber, and the edge at the portion formed in the projecting or recessed shape in the ink chamber) is larger closer to the ink supply opening. That is, the shape of the rim changes from a gentle shape to a sharp shape in the process of approaching the ink supply opening. Therefore, at a position close to the ink supply opening, the capillary force applied to the ink from the rim becomes large. Thus, the ink is guided to the ink supply opening with a part of the edge of the curvature change. In this way, since the occurrence of a situation in which ink remains away from the ink supply opening can be avoided, the ink in the ink chamber can be completely used up, and at a position away from the ink supply opening, the capillary force applied to the ink from the edge due to the attraction is relatively small, so that the ink separates.

In the ink cartridge of one representative aspect of the present invention, at least a part of the plurality of rims extends continuously from the rim at a position higher than the ink supply opening to the rim at the ink supply opening. Therefore, even if the ink surface is lowered as the ink is consumed, the ink can be accurately guided to the ink supply opening with those edges extending continuously from a position higher than the ink supply opening to the ink supply opening and those edges having a larger curvature closer to the ink supply opening. Therefore, it is possible to prevent ink from remaining near the side surface of the ink chamber away from the ink supply opening.

In the ink cartridge of one representative aspect of the present invention, at least a part of the plurality of rims is formed between predetermined two surfaces of the surfaces forming the ink chamber, and a curvature of the rim is different at each junction of the predetermined two surfaces. With such a structure that the curvature of the edge between the two surfaces forming the ink chamber is different in each combination of the two surfaces, it is possible to easily realize such a structure that the curvature of the edge is larger closer to the ink supply opening.

In the ink cartridge of one representative aspect of the present invention, the cut surfaces at the edges are parallel to the predetermined two surfaces, respectively, at the joining portion of the predetermined two surfaces. Therefore, an edge having a predetermined curvature is easily formed between the two surfaces.

An ink cartridge of a representative aspect of the present invention includes a cartridge body formed with an ink chamber; an ink supply opening formed on a bottom surface of the ink chamber and supplying ink to the recording apparatus; and an ink guide portion provided on a bottom surface of the ink chamber, the ink guide portion extending from a side surface of the ink chamber toward the ink supply opening. The curvature of the edge between the ink guide portion and the bottom surface is greater than the curvature of the edge between the side surface and the bottom surface of the ink chamber.

In such an ink cartridge, ink in an ink chamber formed in an ink cartridge main body is supplied to a recording apparatus from an ink supply opening via an ink guide portion extending from a side surface of the ink chamber toward the ink supply opening. The curvature of the edge between the ink guide portion and the bottom surface of the ink chamber is larger than the curvature of the edge between the side surface and the wall surface of the ink chamber. That is, the capillary force applied to the ink at the edge between the ink guiding portion near the ink supply opening and the bottom surface of the ink chamber becomes larger than the capillary force at a position near the side surface of the ink chamber but far from the ink supply opening. Therefore, since it is possible to avoid the occurrence of such a situation that the ink remains at a position away from the ink supply opening where the capillary force applied to the ink from the edge by being attracted is relatively small, the ink separates, it is possible to completely use up the ink in the ink chamber.

In the ink cartridge of one representative aspect of the present invention, the curvature of the edge between the ink guide portion and the bottom surface is larger as it is closer to the ink supply opening. Therefore, even at the edge between the ink guide portion and the bottom surface of the ink chamber, the capillary force applied to the ink is larger closer to the ink supply opening. Therefore, it is possible to accurately prevent ink from remaining at a position away from the ink supply opening.

In an ink cartridge of a representative aspect of the present invention, the ink guide portion extends to the ink supply opening. Therefore, the ink on the bottom surface of the ink chamber can be accurately guided to the ink supply opening via the ink guide portion.

The ink guide portion may be a projection projecting from the bottom surface (eighth invention) or a groove formed on the bottom surface (ninth invention).

In an ink cartridge of a representative aspect of the present invention, a plurality of ink guide portions are provided to converge from the periphery of the ink supply opening to the ink supply opening. Since the plurality of ink guide portions provided are gathered to the ink supply opening from the periphery, the ink on the bottom surface of the ink chamber can be more accurately guided to the ink supply opening.

In an ink cartridge of a representative aspect of the present invention, an edge of the ink guide portion opposite to the ink supply portion extends continuously to a side surface of the ink chamber. Therefore, the ink near the side surface of the ink chamber can be accurately guided to the ink supply opening via the ink guide portion.

In japanese laid-open patent application No. h09-85963, there is given an ink tank (hereinafter referred to as "ink cartridge") which stores ink inside and is provided with an opening at the bottom. An elastic film valve is arranged at the opening of the ink box. The ink cartridge is structured so as to be freely attached to and detached from the holder. With the holder, a protruding portion that opens the valve is formed at a position facing the opening. Through holes are provided at the protruding portions to enable ink in the ink cartridge to flow to the outside. When the ink cartridge is properly mounted to the holder, the protruding portion of the holder pushes the valve upward and opens the valve, and the ink in the ink cartridge flows to the outside through the through-hole and the opening.

However, in the structure of the ink cartridge described above, the valve normally blocks communication between the inside and outside of the ink cartridge, and the projecting portion pushes the valve upward to allow such communication only when the ink cartridge is properly mounted to the holder. However, there is a problem that ink leaks out through the opening if the valve is accidentally pushed up before the ink cartridge is mounted to the holder.

The disclosed embodiments of the present invention have been made in view of the above problems, and provide an ink cartridge capable of minimizing the possibility of ink leakage even if a malfunction occurs before the ink cartridge is mounted to a holder.

An ink cartridge according to a representative aspect of the present invention is detachably mountable to a recording apparatus main body and is equipped with a storage chamber that stores ink. The ink cartridge includes a communication opening formed in the cylindrical wall and communicating with an outside of the ink cartridge, and a cylindrical wall formed at one side of the storage chamber, the ink cartridge further comprising a flow passage having one end communicating with the communication opening and the other end communicating with the storage chamber, the ink cartridge further comprising a valve device having a valve seat portion provided in the communication opening and a valve member structured so as to be able to be connected to and separated from the valve seat portion, the valve device sealing communication between the inside and the outside of the storage chamber when the valve member contacts the valve seat portion, and when the ink cartridge is properly mounted to the recording apparatus main body, the valve element is separated from the valve seat portion by a predetermined distance, thereby allowing communication between the inside and the outside of the storage chamber, and a blocking member for blocking communication between the inside and the outside of the storage chamber by closing the flow passage when the valve member is moved farther than a predetermined distance.

In the ink cartridge according to a representative aspect of the present invention, the flow passage is formed inside a hollow cylindrical member that is erected from the bottom wall toward an upper portion of the ink cartridge. The blocking member is formed by protruding to the flow passage side and protruding in a substantially cylindrical shape having an outer diameter substantially equal to the inner diameter of the flow passage. When the valve member is moved farther than the predetermined distance, at least the leading end of the blocking member comes into engagement by closely contacting the inside of the flow passage.

In the ink cartridge according to a representative aspect of the present invention, the blocking means is held in a closely contacted and fitted state.

In the ink cartridge according to a representative aspect of the present invention, the valve element and the stopper member are integrally formed of a resin material.

In the ink cartridge according to a representative aspect of the present invention, the flow passage is an air introduction passage that introduces air into the ink cartridge.

In an ink cartridge according to a representative aspect of the present invention, the ink cartridge is detachably mounted to a recording apparatus main body and is equipped with a storage chamber that stores ink. The ink cartridge includes a communication opening formed on one side of the ink cartridge so as to be open to the outside, a flow passage communicating the communication opening and the storage chamber, and a stopper member movable in a direction close to the flow passage with the ink cartridge properly mounted to the recording apparatus, the stopper member being spaced apart from the flow passage when properly mounted and closing the flow passage when moved by more than the amount of movement of proper mounting.

The ink cartridge according to a representative aspect of the present invention further includes a sealing means positioned in the communication opening and further outside than the stopper, wherein the sealing means is opened when properly installed.

In the ink cartridge according to a representative aspect of the present invention, the sealing means is composed of a valve seat portion and a valve element capable of contacting and separating from the valve seat portion, and the stopper member is connected to the valve element.

The ink cartridge according to a representative aspect of the present invention further includes an ink supply opening, which is formed at one side of the ink cartridge and opens outward, and which supplies the ink in the storage chamber to the recording apparatus main body. The communication opening is an air introduction opening that introduces air into the storage chamber.

In the ink cartridge according to a representative aspect of the present invention, the stopper front end is structured such that its outer diameter becomes gradually smaller in a direction toward the flow passage.

In the ink cartridge according to a representative aspect of the present invention, the flow passage is structured such that an inner diameter thereof becomes gradually smaller from an end surface on the side of the stopper in a direction away from the stopper.

According to the ink cartridge of the representative aspect of the present invention, when the ink cartridge is properly mounted to the recording apparatus main body, the valve member is separated from the valve seat portion by a predetermined distance, so that the ink storage chamber can communicate with the outside. Additionally, the blocking member closes the flow passage when the valve member is accidentally moved further than the predetermined distance. Thereby minimizing the possibility of ink leakage to the outside.

According to the ink cartridge of the representative aspect of the present invention, the flow passage is formed inside the hollow cylindrical member, which is erected from the bottom wall toward the upper portion of the ink cartridge. The blocking member is formed by protruding to the flow passage side and protruding in a substantially cylindrical shape having an outer diameter substantially equal to the inner diameter of the flow passage. When the valve member is moved farther than the predetermined distance, at least the leading end of the blocking member comes into engagement by closely contacting the inside of the flow passage. And thus has the effect of accurately suppressing ink leakage.

According to the ink cartridge of the representative aspect of the present invention, the stopper member is held in a state of close contact and engagement. Thus having the effect of preventing the ink from continuously leaking.

According to the ink cartridge of the representative aspect of the present invention, since the valve element and the stopper member are integrally formed of the resin material, there are effects of reducing the number of parts and reducing the manufacturing cost.

According to the ink cartridge of a representative aspect of the present invention, the flow path is an air introduction path that introduces air into the ink cartridge. Therefore, when the valve member is moved farther than the predetermined distance, the air introduction passage is blocked by the blocking member, and even if the ink supply opening is opened at this time, air pressure is not applied to the ink cartridge. And thus has the effect of suppressing ink leakage.

According to the ink cartridge of the representative aspect of the present invention, the communication opening is formed at one side of the ink cartridge to be outwardly opened and communicated with the storage chamber by the flow passage. A stopper is disposed in the communication opening and moves in a direction approaching the flow passage as the ink cartridge is properly mounted to the recording apparatus. When the ink cartridge is properly mounted to the recording apparatus main body, the stopper is separated from the flow passage by a certain distance, and when accidentally moved more than a predetermined amount, closes the flow passage. Thereby minimizing the possibility of ink leakage to the outside.

The ink cartridge according to a representative aspect of the present invention further includes a sealing means positioned in the communication opening and further outside than the stopper, wherein the sealing means is opened when properly installed. The sealing means thus accurately seals the communication between the inside and outside of the ink cartridge when the ink cartridge is not mounted to the main body of the recording apparatus. In addition, when the ink cartridge is properly mounted to the recording apparatus main body, the flow path to the outside can be accurately formed.

According to an ink cartridge of a representative aspect of the present invention, the sealing means is composed of a valve seat portion and a valve element capable of contacting and separating from the valve seat portion, and the stopper member is connected to the valve element. Therefore, it becomes unnecessary to form a complicated structure in the ink cartridge to arrange the stopper member and the valve member, as compared with the case where the stopper member and the valve member are separately formed. Thus, the structure of the ink box is simplified.

According to an ink cartridge of a representative aspect of the present invention, the ink cartridge further includes an ink supply opening formed at a side of the ink cartridge and opened outward, which supplies the ink in the storage chamber to the recording apparatus main body. The communication opening is an air introduction opening that introduces air into the storage chamber. Therefore, when the stopper member is moved more than the predetermined movement amount, the flow passage of the introduced air is blocked, and air pressure is not applied to the ink cartridge even if the ink supply opening is opened at this time. And thus has the effect of suppressing ink leakage.

According to the ink cartridge of the representative aspect of the present invention, since the front end of the blocking member is structured such that the outer diameter thereof becomes gradually smaller in the direction toward the flow passage, the front end of the blocking member is easily inserted into the flow passage. And thus has an effect of being able to accurately perform the blocking operation.

According to the ink cartridge of the representative aspect of the present invention, since the flow path is structured such that the inner diameter thereof becomes gradually smaller from the end surface on the side of the stopper in the direction away from the stopper, the stopper can be inserted into the flow path more easily. And thus has an effect of being able to accurately perform the blocking operation.

In japanese laid-open patent application No. h06-64182, there is an ink cartridge which is provided with an air tube (hereinafter referred to as "air introducing member") for introducing air into a main casing of the ink cartridge, and is also provided with a thin film blocking member which is bonded to an upper end of the air introducing member, and a cooperating operating member provided inside the air introducing member. In order to introduce air into the ink cartridge, an air introduction needle passes through a rubber member provided on a bottom wall of the ink cartridge. The air introduction passage is formed by pushing the cooperative operation member to pierce the film piercing member, and the air passes through the narrow hole formed by the cooperative operation member. The narrow hole of the cooperative operation member extends in a direction substantially perpendicular to the bottom wall of the ink cartridge and is formed substantially linearly from the front end opening to the rubber member.

The air introducing member of the ink cartridge introduces an amount of air into the ink cartridge corresponding to the amount of ink supplied from the ink cartridge to the recording head, thereby maintaining the pressure of ink to be supplied to the recording head constant. Therefore, it is preferable that the entering ink does not block the air introduction member. However, the ink cartridge inevitably tilts or falls down after production before the ink cartridge is attached to the recording apparatus main body by a user or once the ink cartridge is detached from the recording apparatus main body by the user. Therefore, there is a possibility that the ink sticks to the open end of the air introduction member or the ink enters the inside of the air introduction member.

When the introduction passage is narrow, the ink often closes the air introduction member by forming a meniscus at the open end on the side of the storage chamber of the air introduction member or forming a meniscus inside the introduction passage of the air introduction member. If ink is supplied in this state, the following phenomenon is repeated: the pressure in the meniscus sealed storage chamber decreases; the air breaks the meniscus and flows into the storage chamber; the meniscus formed by the remaining ink reduces the pressure; and air breaks the meniscus and flows into the storage chamber. That is, the pressure of the ink supplied to the recording head fluctuates, and the ink is unevenly discharged from the recording head. Therefore, a problem of degradation of recording quality occurs.

The embodiments disclosed in the present invention have considered the above-described problems and provide an ink cartridge that keeps ink discharged uniformly from a recording head by preventing pressure fluctuation of ink supply to the recording head by correctly introducing air into the ink cartridge.

An ink cartridge according to a representative aspect of the present invention is provided with a storage chamber for storing an ink and includes an air introduction opening formed in a bottom wall, wherein the bottom wall is a bottom of the storage chamber, the air introduction opening introduces the air into the storage chamber, an ink supply opening which supplies the ink in the storage chamber to the outside, and a hollow cylindrical air introduction member rising from the bottom wall toward an upper portion of the storage chamber, a lower end of an internal flow passage of the air introduction member being communicated with the air introduction opening, and an upper end of the air introduction member being opened in the upper portion of the storage chamber. The air introduction member is structured such that at least a part of the upper end opening is formed diagonally with respect to the first direction, and thus the area of the upper end opening is larger than the cross-sectional area of the internal flow passage in the direction perpendicular to the first direction.

An ink cartridge according to a representative aspect of the present invention is provided with a storage chamber for storing an ink and includes an air introduction opening formed in a bottom wall, wherein the bottom wall is a bottom of the storage chamber, the air introduction opening introduces the air into the storage chamber, an ink supply opening which supplies the ink in the storage chamber to the outside, and a hollow cylindrical air introduction member rising from the bottom wall toward an upper portion of the storage chamber, a lower end of an internal flow passage of the air introduction member being communicated with the air introduction opening, and an upper end of the air introduction member being opened in the upper portion of the storage chamber. The upper end openings of the air introduction members are formed in two or more planes different from each other.

An ink cartridge according to a representative aspect of the present invention is provided with a storage chamber for storing an ink and includes an air introduction opening formed in a bottom wall, wherein the bottom wall is a bottom of the storage chamber, the air introduction opening introduces the air into the storage chamber, an ink supply opening which supplies the ink in the storage chamber to the outside, and a hollow cylindrical air introduction member rising from the bottom wall toward an upper portion of the storage chamber, a lower end of an internal flow passage of the air introduction member being communicated with the air introduction opening, and an upper end of the air introduction member being opened in the upper portion of the storage chamber. The upper end opening of the air introduction member is formed in a non-circular shape.

An ink cartridge according to a representative aspect of the present invention is provided with a storage chamber for storing an ink and includes an air introduction opening formed in a bottom wall, wherein the bottom wall is a bottom of the storage chamber, the air introduction opening introduces the air into the storage chamber, an ink supply opening which supplies the ink in the storage chamber to the outside, and a hollow cylindrical air introduction member rising from the bottom wall toward an upper portion of the storage chamber, a lower end of an internal flow passage of the air introduction member being communicated with the air introduction opening, and an upper end of the air introduction member being opened in the upper portion of the storage chamber. The inner diameter of the internal flow channel of the air introduction member is sized so that a meniscus cannot be formed in a direction in which the ink blocks the internal flow channel.

In the ink cartridge according to one representative aspect of the present invention, an inner diameter of the internal flow passage of the air introduction member is equal to or greater than about 0.8 mm.

An ink cartridge according to a representative aspect of the present invention further includes a side wall extending in a first direction from a periphery of the bottom wall and being an outer periphery of the storage chamber, a main casing structure formed by the bottom wall and the side wall, an open top surface of the main casing, and a cover member covering the open top surface of the main casing, the air introduction member being integrally formed with the bottom wall.

According to the ink cartridge of one representative aspect of the present invention, the air introducing opening is formed on the bottom wall as the bottom of the storage chamber and introduces air into the storage chamber. The lower end of the internal flow passage of the air introduction member communicates with the air introduction opening. The air introduction member rises from the bottom wall toward the upper portion of the storage chamber and has an opening opened in the upper portion of the storage chamber. The air introduction member is structured such that at least a part of the upper end opening is formed diagonally with respect to the first direction, and thus the area of the upper end opening is larger than the cross-sectional area of the internal flow passage in the direction perpendicular to the first direction. The upper end opening of the air introduction member may also be formed by two or more planes different from each other. The upper end opening of the air introduction member may also be formed in a non-circular shape. It is difficult to form a meniscus even if ink sticks to the opening, and even if a meniscus is formed, it is easy to break it with the introduction of air. Therefore, since the fluctuation of the introduced air occurring when the meniscus is formed at the opening can be suppressed, there is an effect of reducing the fluctuation of the ink supplied to the recording head, and the uniform discharge of the ink from the recording head can be maintained.

According to the ink cartridge of one representative aspect of the present invention, the air introducing opening is formed on the bottom wall as the bottom of the storage chamber and introduces air into the storage chamber. The lower end of the internal flow passage of the air introduction member communicates with the air introduction opening. The air introduction member rises from the bottom wall toward the upper portion of the storage chamber and has an opening opened in the upper portion of the storage chamber. Since the inner diameter of the internal flow channel of the air introduction member is sized so that a meniscus cannot be formed in the direction in which the ink blocks the internal flow channel, the internal flow channel is not blocked by a thin film formed by the ink, that is, even if the ink remains in the internal flow channel, the internal flow channel is not blocked by the meniscus. In addition, air is correctly introduced into the storage chamber. Therefore, as described above, there is an effect that uniform ink discharge from the recording head can be maintained.

According to the ink cartridge of one representative aspect of the present invention, this effect can be easily achieved by setting the inner diameter of the internal air passage of the air introducing member to about 0.8mm or more.

According to an ink cartridge of a representative aspect of the present invention, the main casing is a structure having an open top surface formed by a bottom wall and a side wall. In addition, the air introduction member is formed integrally with the bottom wall. Therefore, since the main casing integrally provided with the air introduction member is easily formed by molding, the manufacturing cost can be reduced, and the flow of ink from the connection ports of the air introduction member and the bottom portion to the internal flow passage can be prevented. Thus having the effect of correctly introducing air into the storage compartment.

In japanese laid-open patent application No.6-64182, there is an ink cartridge that is provided with an air tube (hereinafter referred to as "air introducing member") for introducing air into the inside of a main casing of the ink cartridge. The ink cartridge further has a rubber member at the bottom thereof, through which the ink supply needle and the air introduction needle are inserted. On the rubber member, an air introduction member is mounted by being bonded to the main casing. In addition, the upper end of the air introduction member is formed as a flat surface portion having a diameter larger than the outer diameter of the air introduction member for bonding the membrane block member to prevent the flow from entering. A cooperating operating member is disposed within the air intake member that pierces the membrane barrier. To introduce air into the interior of the ink cartridge, an air introduction needle passes through the rubber member and pushes up the cooperative operation member, so that the cooperative operation member pierces the film stopper to allow air to be introduced into the interior of the ink cartridge.

However, since the main casing and the air introduction member are separate bodies in the above-described ink cartridge, it is necessary to mount the air introduction member to the main casing, and the operation efficiency is lowered, resulting in an increase in manufacturing cost. In addition, since air may enter the internal flow path of the air introduction member from the connection point between the ink cartridge and the air introduction member, there is a problem in that the air cannot be correctly introduced.

In addition, in order to manufacture the ink cartridge in which the main casing and the air introduction member are integrated so that the operation efficiency can be improved, since the upper end of the air introduction member is formed as a flat surface having a diameter larger than the outer diameter of the air introduction member, there is a problem in that the manufacturing process is complicated when manufacturing by a molding method, thereby increasing the manufacturing cost.

The disclosed embodiments of the present invention take the above-described problems into consideration and provide an ink cartridge that can reduce the manufacturing cost of the ink cartridge and can correctly introduce air into an ink chamber.

An ink cartridge according to a representative aspect of the present invention has a storage chamber storing ink and includes a main casing having a bottom wall and a side wall forming the storage chamber, and a top surface of the main casing is open, an air introduction opening formed in the bottom wall of the main casing for introducing air into the storage chamber, an ink supply opening formed in the main casing for supplying ink in the storage chamber to the outside, and a hollow cylindrical air introduction member whose internal flow passage communicates with the air introduction opening, the hollow cylindrical air introduction member being formed integrally with the bottom wall of the main casing and rising from the bottom wall of the main casing toward the open upper surface in a first direction, an upper end of the air introduction member being open above the ink surface in the storage chamber.

In the ink cartridge according to one representative aspect of the present invention, a connecting portion of the air introduction member and the bottom wall is formed in a shape expanding from the air introduction member to the bottom wall.

In an ink cartridge according to a representative aspect of the present invention, the air introduction opening is formed in a first cylindrical wall that protrudes from and is integrally formed with a lower surface of the bottom wall. The ink supply opening is formed in a second cylindrical wall projecting from and formed integrally with the lower surface of the bottom wall, and the air introduction opening and the ink supply opening are sealed with sealing means provided in the first cylindrical wall and the second cylindrical wall.

In the ink cartridge according to one representative aspect of the present invention, the first cylindrical wall and the air introduction member are integrally formed in a continuous cylindrical shape in a direction intersecting the bottom wall.

In the ink cartridge according to a representative aspect of the present invention, the sealing means is a valve device provided with a valve seat portion and a valve member, the valve member being movable relative to the valve seat portion, and the valve device being moved in a direction in which the valve member is separated from the valve seat portion as the ink cartridge is mounted to the ink jet recording apparatus.

According to an ink cartridge of a representative aspect of the present invention, the ink cartridge has a storage chamber for storing ink, and is constituted by a main casing having a bottom wall and a side wall forming the storage chamber, and a top surface of the main casing is open, and a cover member covering the open top surface of the main casing. An air introduction opening is formed in the bottom wall of the main casing for introducing air into the storage chamber. In addition, an internal flow passage of a hollow cylindrical air introduction member, which is formed integrally with the bottom wall of the main casing and rises from the bottom wall of the main casing toward the open upper surface in the first direction, is communicated with the air introduction opening, and an upper end of the air introduction member is open above the ink surface in the storage chamber. The internal flow passage of the air introduction member communicates with the air introduction opening, and is capable of introducing air into the storage chamber through the air introduction opening and the air introduction member. Therefore, since the upper surface of the main casing is open, and since the air introduction member is formed by being integrally raised from the bottom wall toward the open surface, the main casing and the air introduction member are easily molded with resin by a method such as molding. Therefore, since the number of parts is reduced and it is not necessary to assemble the main housing and the air introduction member, the operation efficiency is improved and the manufacturing cost is reduced.

In addition, since the main casing and the air introduction member are integrally formed, it is possible to prevent ink from flowing into the internal flow passage of the air introduction member from the connection portion between the main casing and the air introduction member. Therefore, there is an effect that air can be correctly introduced into the storage chamber.

According to the ink cartridge of one representative aspect of the present invention, since the connecting portion of the air introduction member and the bottom wall is formed in a shape expanding from the air introduction member to the bottom wall, there is an effect that the strength at the connecting point is increased and the air introduction member is not easily deformed at the time of molding or at the time of subsequent environmental change.

According to the ink cartridge of one representative aspect of the present invention, the air introduction opening is formed in a first cylindrical wall that protrudes from and is integrally formed with the lower surface of the bottom wall, the ink supply opening is formed in a second cylindrical wall that protrudes from and is integrally formed with the lower surface of the bottom wall, and the air introduction opening and the ink supply opening are sealed with the sealing means provided in the first cylindrical wall and the second cylindrical wall. Therefore, when the first cylindrical wall and the second cylindrical wall are molded integrally with the main casing by molding or the like, the inside of the ink cartridge can be brought into a sealed state by disposing the sealing means at the first cylindrical wall and the second cylindrical wall. Therefore, there is an effect of further improving the efficiency of the mounting operation.

According to the ink cartridge of one representative aspect of the present invention, the first cylindrical wall and the air introducing member are integrally formed in a continuous cylindrical shape in a direction intersecting the bottom wall. Therefore, even if the ink flows into the internal flow passage of the air introduction member during transportation of the ink cartridge, the ink in the internal flow passage can smoothly flow into the storage chamber when the ink cartridge is mounted so as to open the air introduction opening. Therefore, since the ink in the internal flow channel of the air introduction member does not block the introduced air, there is an effect that the air can be correctly introduced.

According to an ink cartridge of a representative aspect of the present invention, the sealing means is a valve means provided with a valve seat portion and a valve member, the valve member being movable relative to the valve seat portion and the valve means being movable in a direction in which the valve member is spaced from the valve seat portion as the ink cartridge is mounted to the ink jet recording apparatus. This has the effect of preventing the occurrence of ink leakage when the ink cartridge is not properly mounted to the ink jet recording apparatus, and accurately forming the air introduction passage and the ink supply passage by moving the valve member of the valve device in the direction away from the valve seat portion when the ink cartridge is mounted to the ink jet recording apparatus.

While the invention has been described above in connection with representative embodiments and examples, it will be apparent to those skilled in the art that various other alternative embodiments, modifications, variations, improvements, and/or equivalents may exist, whether known or presently unforeseen. Accordingly, the above-described exemplary embodiments of the invention are intended to be illustrative, not limiting. Various changes can be made without departing from the spirit and scope of the invention. Accordingly, the above disclosure is intended to embrace all known and later-developed alternatives, modifications, variations, improvements, and/or equivalents.

Industrial applicability

The ink cartridge of the present invention is mounted in an ink jet recording apparatus which is widely used in homes and offices.

Claims

1. An ink cartridge configured to be mounted in an inkjet recording apparatus, the ink cartridge comprising:

an ink chamber;

an air introducing opening which introduces air into the inside of the ink chamber;

a first seal member capable of blocking and allowing communication between the air introduction opening and an area outside the ink cartridge, the first seal member including a first valve seat and a first valve movable relative to the first valve seat;

an ink supply opening which supplies ink from the ink chamber;

a second seal member capable of blocking and allowing communication between the ink supply opening and an area outside the ink cartridge, the second seal member including a second valve seat and a second valve movable relative to the second valve seat; and

a check valve provided between the second seal and the ink chamber, wherein the check valve blocks a flow of ink from an area outside the ink supply opening to the ink chamber in the ink supply opening,

wherein

Configuring the first seal such that the first valve is urged against the first valve seat to block communication between the air introduction opening and the area outside the ink cartridge before the ink cartridge is mounted in the ink jet recording apparatus, and the first valve is separated from the first valve seat to allow communication between the air introduction opening and the area outside the ink cartridge when the ink cartridge is mounted in the ink jet recording apparatus;

configuring the second sealing member such that the second valve is urged against the second valve seat to block communication between the ink supply opening and an area outside the ink cartridge before the ink cartridge is mounted in the ink jet recording apparatus, and the second valve is separated from the second valve seat to allow communication between the ink supply opening and the area outside the ink cartridge when the ink cartridge is mounted in the ink jet recording apparatus; and is

Before the ink cartridge is mounted in the ink jet recording apparatus, the ink chamber is depressurized.

2. The ink cartridge as claimed in claim 1, wherein the air introduction opening and the ink supply opening are formed at one side of the ink chamber.

3. The ink cartridge as claimed in claim 1, wherein the check valve blocks the ink supply opening only when ink flows from an area outside the ink supply opening to the ink chamber.

4. The ink cartridge of claim 2, wherein:

the air introduction opening is in direct communication with the interior of the first cylindrical wall on the first side of the ink chamber,

the ink supply opening is in direct communication with the interior of the second cylindrical wall on the first side of the ink chamber, and

a first seal member is provided inside the first cylindrical wall to seal the air introduction opening, and a second seal member is provided inside the second cylindrical wall to seal the ink supply opening.

5. The ink cartridge of claim 3, wherein:

the check valve includes a shaft portion and a film portion, the film portion being positioned to face the ink supply opening at a predetermined distance from the ink supply opening, an

When ink flows from the area outside the ink supply opening to the ink chamber, the thin film portion closely contacts and blocks the ink supply opening.

6. The ink cartridge of claim 1, wherein:

the check valve includes a shaft portion, a thin film portion and a protrusion portion at one end of the shaft portion,

the projection portion rests on top of the ink supply opening; and

the thin film portion moves toward the ink supply opening when the ink flows toward the ink chamber.

7. The ink cartridge as claimed in claim 1, wherein the check valve closely contacts and blocks the ink supply opening when a predetermined amount of ink flows from an area outside the ink supply opening to the ink chamber.

8. The ink cartridge as in claim 1, wherein the first seal further comprises an operating member that extends from the first valve toward an exterior of the ink cartridge and is operable to move the first valve relative to the first valve seat.